                        Docket No. 101844.


                       IN THE
                  SUPREME COURT
                         OF
                THE STATE OF ILLINOIS




NICOR, INC., et al., Appellants, v. ASSOCIATED ELECTRIC AND
GAS INSURANCE SERVICES LIMITED et al. (Certain
     Underwriters at Lloyd’s of London et al., Appellees).

                 Opinion filed November 30, 2006.



    JUSTICE KARMEIER delivered the judgment of the court, with
opinion.
    Chief Justice Thomas and Justices Freeman, Fitzgerald, Kilbride,
and Garman concurred in the judgment and opinion.
    Justice Burke took no part in the decision.



                            OPINION

     Nicor, Inc., and Northern Illinois Gas Company, doing business
as Nicor Gas Company (hereinafter referred to collectively as Nicor),
are in the business of supplying natural gas to homes and businesses
throughout northern Illinois. The litigation before us today concerns
the obligation of certain of Nicor’s liability insurance carriers to
indemnify the company for sums it expended in connection with the
remediation of mercury contamination caused by the removal of gas
meter regulators from the homes of its residential customers between
1961 and 1978. During the course of the litigation, which spanned a
four-year period between 2000 and 2004, some of the defendant
insurance carriers settled. The defendants designated by the parties as
“certain underwriters at Lloyd’s of London and certain London
market insurance companies” (the London Insurers) did not. In late
2004, the circuit court entered judgment in favor of Nicor and against
the London Insurers in the amount of $10,281,703.46. The London
Insurers appealed. The appellate court reversed and remanded for
further proceedings on the sole ground that the circuit court had
misapplied the terms of the applicable insurance policies. 362 Ill. App.
3d 745. We granted Nicor’s petition for leave to appeal. 177 Ill. 2d R.
315. For the reasons that follow, we now affirm the appellate court’s
judgment.

                           BACKGROUND
     Nicor installs meters at the homes of its residential customers to
measure the amount of natural gas the customers consume. Each
meter contains a regulator which controls the flow of natural gas into
the residence. The regulators decrease the high pressure used to
transport natural gas through the delivery system to the lower
pressures utilized within customers’ homes. As a safety feature, the
regulators include a relief valve that opens if the pressure of the gas
being supplied to a customer’s home is excessive.
     Until 1961, Nicor utilized gas meters whose regulators included
relief valves containing the metallic element mercury. The quantity of
mercury in a given unit ranged from 1½ to 4 ounces. The mercury,
which remained liquid at room temperature, served as a “cap” on the
relief valve. If the gas pressure in the system was too high, it would
force the mercury “cap” aside, enabling the gas to pass through a vent
and escape safely to the outside of the home.
     Beginning in 1961, Nicor initiated a systemwide program to
remove regulators containing mercury from inside their customers’
homes and to replace them with new regulators utilizing a spring-
activated relief mechanism. The new regulators with spring-activated
relief valves were part of temperature-compensating meter sets that
could be installed on the outside of customers’ homes. No mercury
was used in any part of these replacement meter sets.
     In implementing its replacement program during this period,
Nicor did not dispatch crews specifically to exchange meters. New

                                  -2-
meters were installed only if an old-style meter was discovered by a
Nicor service crew sent to the area for some other reason, such as to
perform maintenance or repair work at a customer’s home or to
upgrade a neighborhood’s natural gas service. Whenever a Nicor crew
found that a customer’s meter set was located in the house, it would
remove that meter set and install one of the new temperature-
compensating meters outside the residence. As part of this process,
the Nicor crew would replace the old regulator containing a mercury
relief valve with one of the new regulators equipped with a spring-
activated relief valve.
      The replacement process was normally safe and unremarkable. In
a very small number of cases, however, regulators were tilted or
tipped in a way that allowed mercury to spill out and contaminate the
customer’s home. The problem of contamination surfaced during the
summer of 2000, when Nicor learned that a contractor it had hired
had spilled mercury in a customer’s home while removing one of the
old regulators.
      The initial contamination report was followed by revelations that
additional mercury spills had occurred in the homes of other Nicor
customers. Class actions seeking damages for personal injury and
property damage were soon instituted against the company on behalf
of all those who had been affected by the mercury spills resulting from
the replacement of the old-style regulators. The Illinois Attorney
General, joined by the State’s Attorneys of Cook, Du Page and Will
Counties, also brought a separate suit against Nicor in the circuit
court of Cook County. The Attorney General’s action demanded,
inter alia, that Nicor be required to investigate the extent of mercury
contamination caused by replacement of its natural gas regulators, to
clean up the contamination, and to assist all potentially affected
individuals in determining whether they had suffered any mercury
exposure.
      Nicor was able to reach a settlement with the Attorney General’s
office shortly after it filed its action. The class actions were
consolidated and settled as well. Under the terms of the settlement in
the Attorney General’s action, Nicor was required to identify all
homes within its service area that may have been contaminated by
mercury from an old-style regulator and to undertake appropriate
measures to clean up any contamination that was detected. Nicor

                                 -3-
subsequently ascertained that over 300,000 of its customers’ homes
may have had regulators with relief valves containing mercury.
Approximately one third of those homes were determined to have
been constructed after the period when the old-style relief valves were
no longer being installed in new construction and were therefore not
at risk for mercury contamination. The remaining 200,000 homes were
physically inspected. Of those, 1,070, or approximately one-half of
1%, were found to contain impermissibly high levels of mercury. For
the purposes of this litigation, the parties have stipulated that the
mercury found in those 1,070 homes “was more likely than not due to
the removal of mercury-containing regulators from inside the homes.”
      The process of investigating, identifying and remediating the
mercury contamination in its customers’ homes cost Nicor
approximately $90 million. Nicor turned to its insurers to obtain
indemnification for those expenses. When the insurers refused to pay
Nicor’s claims, the company brought this action against them in the
circuit court of Cook County. Nicor’s suit sought declaratory relief
and damages based on breach of contract and anticipatory breach of
contract.
      All of the defendant insurance carriers that were still solvent
agreed to a settlement with Nicor, with the exception of the London
Insurers. Nicor had purchased polices from the London Insurers
between 1961 and 1978. The policies issued by the London Insurers
were excess/umbrella general liability policies under which the insurers
were required to indemnify Nicor for all sums Nicor became legally
obligated to pay because of property damage caused by or growing
out of “an occurrence.” Under the policies issued between 1961 and
November 1976, an “occurrence” was defined as “one happening or
series of happenings arising out of or due to one event taking place
during the term of this contract.” The policies issued from November
1976 through 1978 defined an “occurrence” as:
             “(1) an accident, or (2) event or continuous or repeated
          exposure to conditions which result in bodily injury, personal
          injury, death or physical damage to or destruction of tangible
          property, including the loss of use. All damages arising out of
          such exposure to substantially the same general conditions
          shall be considered as arising out of one occurrence.”


                                  -4-
     Under all of the London Insurers’ policies, the insurers’
obligation to provide indemnification was subject to a self-insured
retention (SIR), that is, a deductible. The amount of the deductible
varied, but was never less than $100,000 per occurrence. Nicor
therefore could not obtain indemnification from the London Insurers
unless and until its loss for a covered occurrence was more than
$100,000. Once the SIR amount had been satisfied, the London
Insurers were obligated to indemnify only for the amount in excess of
the SIR up to a contractually specified limit of liability. The liability
limitations ranged from $750,000 to more than $4 million depending
on the policy.
     Of the 1,070 homes where mercury contamination was
discovered and remediation was carried out, 195 were subject to the
policies issued to Nicor by the London Insurers between 1961 and
1978. For the purposes of this litigation, there is no dispute that the
investigation and remediation costs attributable to each of those 195
homes, individually, was less than the applicable SIR amount. How
the term “occurrence” was construed under the governing policies
therefore had major consequences for calculating the extent of the
London Insurers’ duty to provide indemnification. If each of the 195
spills constituted a separate occurrence within the meaning of the
policies, the London Insurers would owe nothing. If, on the other
hand, the spills were conceived as constituting but a single occurrence,
the amount the London Insurers would be required to pay Nicor
would be substantial.
     In order to resolve the occurrence issue, Nicor and the London
Insurers filed cross-motions for summary judgment pursuant to
section 2–1005 of the Code of Civil Procedure (735 ILCS 5/2–1005
(West 2004)). Nicor, for its part, asserted that its liability for the
mercury contamination at the 195 homes arose from one occurrence,
obligating it to pay a single SIR per policy year to cover all of the
contamination claims. The London Insurers, by contrast, contended
that Nicor’s liability arose from 195 separate occurrences and that
Nicor’s claims were therefore subject to 195 separate SIRs.
     The circuit court denied the London Insurers’ motion, but
granted summary judgment in favor of Nicor. In the circuit court’s
view, the contamination was attributable to Nicor’s consistent and
routine “failure to invoke proper procedures to safely remove the

                                  -5-
mercury regulators.” The court held that this “systematic failure to
consistently remove the mercury regulators resulted in a single
‘occurrence’ under the [London Insurers’] policies.”
      Following the circuit court’s ruling, Nicor and the London
Insurers stipulated to the remaining issues in the case, including: (1)
that mercury spills took place in every policy period between 1961
and 1978, (2) that the SIRs under the policies in effect during those
years totaled $950,000, and (3) that the London Insurers’ pro rata
liability for the $90 million in losses ultimately incurred by Nicor after
satisfaction of the $950,000 in SIRs totaled $10,281,703.46. Based
upon these stipulated facts, the circuit court entered final judgment in
favor of Nicor and against the London Insurers in the amount of
$10,281,703.46.
      As noted at the outset of this opinion, the appellate court
reversed and remanded for further proceedings. 362 Ill. App. 3d 745.
The sole ground for its decision was that the circuit court had
misapplied the definition of occurrence contained in the applicable
insurance policies. In the appellate court’s view, the damages were not
caused by Nicor’s systemwide failure to remove the regulators safely.
Rather, they were the product of separate and independent acts,
occurring “in an isolated number of cases as a result of [individual
servicemen’s] actions or the particular circumstances in each
residence.” 362 Ill. App. 3d at 754.
      Nicor petitioned our court for leave to appeal. 177 Ill. 2d R. 315.
We granted its petition. We subsequently allowed BorgWarner, Inc.,
to file an amicus curiae brief in support of Nicor. See 155 Ill. 2d R.
345. We also allowed John Crane, Inc., to file an amicus curiae brief
in favor of the London Insurers.

                             ANALYSIS
     The sole issue raised by Nicor in this appeal is whether the circuit
correctly held that the mercury contamination in the 195 homes for
which it submitted claims under the policies it purchased from the
London Insurers between 1961 and 1978 constituted a single
occurrence within the meaning of those policies. The construction of
the provisions of an insurance policy is a question of law, subject to



                                   -6-
de novo review. Illinois Farmers Insurance Co. v. Marchwiany, No.
101598, slip op. at 3 (September 21, 2006).
      Insurance policies are subject to the same rules of construction
applicable to other types of contracts. See Continental Casualty Co.
v. McDowell & Colantoni, Ltd., 282 Ill. App. 3d 236, 241 (1996). A
court’s primary objective is to ascertain and give effect to the
intention of the parties as expressed in the agreement. Crum & Forster
Managers Corp. v. Resolution Trust Corp., 156 Ill. 2d 384, 391
(1993). In performing that task, the court must construe the policy as
a whole, taking into account the type of insurance purchased, the
nature of the risks involved, and the overall purpose of the contract.
Travelers Insurance Co. v. Eljer Manufacturing, Inc., 197 Ill. 2d 278,
292 (2001), quoting American States Insurance Co. v. Koloms, 177
Ill. 2d 473, 479 (1997).
      The words of a policy should be accorded their plain and ordinary
meaning. State Farm Mutual Automobile Insurance Co. v. Villicana,
181 Ill. 2d 436, 441 (1998). Where the provisions of a policy are clear
and unambiguous, they will be applied as written (United States Fire
Insurance Co. v. Schnackenberg, 88 Ill. 2d 1, 4 (1981)) unless doing
so would violate public policy (State Farm Mutual Automobile
Insurance Co. v. Villicana, 181 Ill. 2d at 442). That a term is not
defined by the policy does not render it ambiguous, nor is a policy
term considered ambiguous merely because the parties can suggest
creative possibilities for its meaning. Rather, ambiguity exists only if
the term is susceptible to more than one reasonable interpretation.
Lapham-Hickey Steel Corp. v. Protection Mutual Insurance Co., 166
Ill. 2d 520, 530 (1995).
      Because insurance contracts are issued under given
circumstances, they are not to be interpreted in a factual vacuum. A
policy term that appears unambiguous at first blush might not be such
when viewed in the context of the particular factual setting in which
the policy was issued. Glidden v. Farmers Automobile Insurance
Ass’n, 57 Ill. 2d 330, 336 (1974). Governing legal authority must, of
course, be taken into account as well, for a policy term may be
considered unambiguous where it has acquired an established legal
meaning. United States Fire Insurance Co. v. Schnackenberg, 88 Ill.
2d at 5. Where ambiguity does exist, the policy will be construed
strictly against the insurer, who drafted the policy (Travelers

                                  -7-
Insurance Co. v. Eljer Manufacturing, Inc., 197 Ill. 2d at 293), and
liberally in favor coverage for the insured (see Hobbs v. Hartford
Insurance Co. of the Midwest, 214 Ill. 2d 11, 17 (2005)).
      As we have just discussed, the case before us today concerns
construction of the provisions in Nicor’s insurance policies dealing
with occurrences. The question is not, however, whether a covered
occurrence took place. The London Insurers do not dispute that
events transpired which would qualify as an occurrence within the
meaning of both versions of the liability policies issued to Nicor by the
London Insurers between 1961 and 1978. The issue presented by this
litigation is more complex. The problem with which the lower courts
wrestled and which we must now resolve is how many occurrences
there were, 1 or 195.
      The definitions of occurrence used in the insurance policies issued
by the London Insurers are typical of commercial liability policies. As
in our case, such policies often describe an occurrence using terms
such as “accident,” “happening” or “event.” While the form of such
terms is singular, what seems like a single accident, happening, or
event to the person who triggered the incident giving rise to the loss
for which coverage is sought may be perceived as multiple accidents,
happenings or events from the perspective of those who sustained
injury or damage as a result of the insured’s conduct. Accordingly, the
terms of the insurance policy are not always sufficient, standing alone,
to permit a definitive determination as to whether a particular case
involves one occurrence or many.
      In order to overcome this problem, American courts have
developed two basic approaches for assessing the number of
occurrences that took place within the meaning of policies such as
those at issue in this case, the cause theory and the effect theory. The
effect theory, as its name implies, determines the number of accidents
or occurrences by looking at the effect an event had, i.e., how many
individual claims or injuries resulted from it. Under the cause theory,
on the other hand, the number of occurrences is determined by
referring to the cause or causes of the damages. See Illinois National
Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d 1091, 1094-95
(1989).
      The difference between these two approaches is illustrated by the
following hypothetical. Assume that a motorist is traveling down a

                                  -8-
street lined with parked cars. Looking away from the roadway to
change the station on his car’s radio, the motorist allows his vehicle
to wander. As a result, his car strikes the sides of three of the parked
cars in succession, damaging each of them. The owners of the three
damaged vehicles sue, and the vehicle owner seeks indemnification
from his automobile insurance carrier. Under the effect theory, the fact
that three cars were damaged and three claims were filed would mean
that there were three “occurrences” for purposes of determining
liability coverage, absent specific policy language to the contrary.
Under the cause theory, on the other hand, the fact that the damage
to all three vehicles resulted from the same conditions and was
inflicted as part of an unbroken and uninterrupted continuum would
yield the conclusion that there was only one occurrence. See Illinois
National Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d at 1095-96
(discussing application of cause theory to traffic accidents).
      Neither the cause theory nor the effect theory inevitably favors
one party to an insurance contract over another. Whether a particular
approach would be more beneficial to the insurance carrier or its
insured depends on the limits of coverage, the number of claims, the
magnitude of the claimant’s losses, and the size of applicable
deductibles in a given case. For example, attributing damages
sustained by multiple claimants to multiple occurrences would be
beneficial to the insured where the claims are large relative to the per-
occurrence policy limits, for it would maximize the coverage the
insured will receive. It would benefit the insurance carrier where, as
in this case, the individual claims are each smaller than the applicable
deductible, for it would allow the insurer to avoid paying anything.
The full loss would be borne by the insured.
      A majority of jurisdictions have adopted the cause theory to
determine the number of occurrences under general liability insurance
policies of the type at issue in this case. Although this court has not
addressed the issue, our appellate court has consistently concluded
that the cause theory represents the approach which the courts of
Illinois should follow. See Aetna Casualty & Surety Co. v. O’Rourke
Bros., Inc., 333 Ill. App. 3d 871, 881-82 (2002); Illinois Central R.R.
Co. v. Accident & Casualty Co. of Winterthur, 317 Ill. App. 3d 737,
745-46 (2000); United States Gypsum Co. v. Admiral Insurance Co.,
268 Ill. App. 3d 598, 648 (1994); Illinois National Insurance Co. v.

                                  -9-
Szczepkowicz, 185 Ill. App. 3d at 1094-95; Mason v. Home Insurance
Co. of Illinois, 177 Ill. App. 3d 454, 459-60 (1988). In accordance
with this line of authority, the appellate court’s decision in the case
before us adhered to the cause theory in construing and applying the
subject policies. Neither Nicor nor the London Insurers question that
aspect of the appellate court’s decision, and we agree that the cause
theory represents the law of Illinois.
      To properly understand the cause theory as interpreted and
applied in Illinois, one must consider the principal appellate court
cases in which the doctrine has been employed. The first opinion to
adopt the cause theory was Mason v. Home Insurance Co. of Illinois,
177 Ill. App. 3d 454 (1988). Mason was a declaratory judgment
action to determine the amount of liability coverage available to the
owner of a restaurant with respect to claims brought by restaurant
diners who were stricken with botulism poisoning after consuming
patty melt sandwiches containing tainted onions. The tainted food was
served to numerous customers over a three-day period. Applying the
cause theory, the appellate court held that the restaurant did not
become liable until it actually served a portion of the tainted food and
that each time a customer was served constituted a separate and
distinct occurrence within the meaning of the policy. Mason v. Home
Insurance Co. of Illinois, 177 Ill. App. 3d at 461. In reaching this
conclusion, the court distinguished situations where there was an
uninterrupted and continuing cause from which all of the injuries
resulted, such as where guests’ property is damaged in a hotel fire or
when an open faucet on an upper floor of a building causes water
damage to property on lower floors. Mason v. Home Insurance Co.
of Illinois, 177 Ill. App. 3d at 461.
      Mason derived its analysis from a federal court opinion,
Michigan Chemical Corp. v. American Home Assurance Co., 728
F.2d 374 (6th Cir. 1984), a declaratory judgment action to determine
how much insurance coverage was available to pay farmers who had
sustained property damage when their livestock consumed tainted
feed. The contamination occurred when Michigan Chemical
Corporation (MCC). accidently filled an order for a livestock feed
supplement with flame retardant, the feed vendor failed to realize the
mistake, and the flame retardant was mixed with regular feed and sold
to farmers. As a result of the mistake, tens of thousands of farm

                                 -10-
animals had to be destroyed, and hundreds of claims were
subsequently filed against MCC and the feed vendor.
     MCC and a reinsurance company involved in the case argued that
each of the claims constituted a separate occurrence within the
meaning of the applicable insurance policies. The federal court
rejected that argument. Following the view it believed the courts of
Illinois would adopt if presented with the question, it held that the
number of occurrences was determined not on the basis of the number
of injuries, but on the cause or causes of the injuries. In its opinion,
the cause of the injury from which MCC’s liability arose was the
misshipment of the flame retardant and that each separate
misshipment, if more than one took place, would constitute a separate
occurrence. Michigan Chemical Corp. v. American Home Assurance
Co., 728 F.2d at 383.
     The foregoing decisions were followed by Illinois National
Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d 1091 (1989). In that
case, an insurance company brought a declaratory judgment action to
ascertain the amount it was obligated to pay under a liability insurance
policy for two lawsuits filed against its insureds. Those lawsuits arose
from collisions involving a tractor-trailer unit driven by the defendant
and two automobiles. At the time of the collisions, the left rear side
clearance light of the tractor-trailer unit was inoperable and there was
fog in the area.
     The first collision took place when the defendant blocked traffic
while preparing to turn and a motorist struck the rear wheels of his
rig. After this initial accident, the defendant moved the rig forward
and stopped again. In so doing, he failed to completely remove the
tractor-trailer unit from all lanes of traffic. Approximately five minutes
later, another automobile smashed into the rig, just forward of the
point of impact in the first crash. The question in the case was whether
these events constituted one accident or occurrence or two within the
meaning of the defendant’s liability insurance policy, under which
coverage was limited to $300,000 per accident.1


  1
    For purposes of construing the relevant insurance policy provisions, the
appellate court considered “accident” to be synonymous with “occurrence.”
Illinois National Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d at 1094.

                                   -11-
      Looking to the language of the policy and the facts of the case,
the appellate court concluded that under the cause theory, the two
collisions could not be said to have resulted from the same negligent
act. Distinguishing situations where one car ricochets off another and
then strikes a third vehicle, the court held that there was no single
force and no unbroken or uninterrupted continuum that, once set in
motion, caused multiple injuries. The court further noted that the
conditions resulting in each collision had changed. After the first
accident, the defendant should have realized the risk posed in allowing
his rig to obstruct traffic lanes while it was foggy. He had the
opportunity to take corrective measures by moving the rig off the
road, but failed to do so. Instead, by remaining on the roadway and
moving forward, which opened a path for traffic that had been
blocked at the time of the first collision, he created a new and different
hazard to navigation for cars following from behind. The court
therefore concluded that there was a separate and second cause for
the subsequent collision and that there were two accidents or
occurrences under the relevant insurance policy. Illinois National
Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d at 1096.
      Two years afer Illinois National Insurance Co. v. Szczepkowicz,
185 Ill. App. 3d 1091 (1989), the appellate court decided Village of
Camp Point v. Continental Casualty Co., 219 Ill. App. 3d 86 (1991).
Camp Point was a declaratory judgment action brought by a village
against its attorney and his insurance company to determine how much
coverage was available for the attorney’s alleged malpractice under a
series of professional liability policies which the insurance company
had issued. The basis for the underlying malpractice claim was that the
attorney had advised the village that it could pledge revenue-sharing
and sales tax funds in connection with multiple bond transactions
when he knew that such pledges were not approved by statute. The
trial court construed the case as involving one unified transaction,
namely, the attorney’s misinterpretation of the governing law when
advising the village pursuant to a contract of employment which was
to be performed over an extended period of time, and that there was
therefore only one occurrence within the meaning of the attorney’s
professional liability policies. Village of Camp Point v. Continental
Casualty Co., 219 Ill. App. 3d at 97. The appellate court, however,
rejected that interpretation. It held that each individual instance in

                                  -12-
which the attorney rendered erroneous legal advice was a separate
cause of the village’s injuries and that there were therefore multiple
occurrences for insurance coverage purposes. Village of Camp Point
v. Continental Casualty Co., 219 Ill. App. 3d at 103.
     The same approach was taken in Roman Catholic Diocese of
Joliet, Inc. v. Lee, 292 Ill. App. 3d 447 (1997), a declaratory
judgment action to determine, inter alia, whether multiple acts of
sexual molestation committed by a priest against a female minor
constituted a single occurrence within the meaning of the insurance
policies held by the Diocese in which the priest served. The appellate
court held that it did not. Relying on Mason v. Home Insurance Co.
of Illinois, 177 Ill. App. 3d 454 (1988), and decisions from other
jurisdictions, and based on the facts of the case and the language of
the applicable policies, the court held that it was the repeated
exposure of the minor to the negligently supervised priest that
provided the basis for indemnification and that, “[a]ccordingly, the
minor’s exposure to the negligently supervised priest in each of the
policy periods constituted a separate occurrence.” Roman Catholic
Diocese of Joliet, Inc. v. Lee, 292 Ill. App. 3d at 455.
     To the same effect is Illinois Central R.R. Co. v. Accident &
Casualty Co. of Winterthur, 317 Ill. App. 3d 737 (2000), an action
between a railroad and its insurance carriers to determine the extent
of the carriers’ obligation to indemnify the railroad for over $13
million in defense and settlement costs it incurred as the result of
discriminatory hiring decisions made by one of its employees. In that
case, the railroad argued that only a single occurrence was involved,
namely, its decision to delegate hiring decisions to the employee who
made the decisions which subjected it to liability. The appellate court
rejected that contention. Under its view of the cause theory, the
discriminatory hiring decisions did not comprise the continuation of
a single process or condition, but rather were the product of multiple
individual acts which took place over an extended period of time. The
court therefore concluded that each of the discriminatory hiring
decisions was a separate occurrence within the meaning of the
governing policy provisions. Illinois Central R.R. Co. v. Accident &
Casualty Co. of Winterthur, 317 Ill. App. 3d at 746-50.
     In all of the foregoing cases, the insurance policies’ definition of
occurrence was similar to the definitions contained in the policies

                                  -13-
involved in this case. The policy in Mason defined an occurrence as
either an accident or happening or event or a continuous or repeated
exposure to conditions which unexpectedly and unintentionally causes
injury. It further stated that all damages arising out of such exposure
to substantially the same conditions shall be considered as arising out
of one occurrence. Mason, 177 Ill. App. 3d at 459.
     In Michigan Chemical Corp. v. American Home Assurance Co.,
one set of policies defined occurrence as “an accident or a happening
or event or a continuous or repeated exposure to conditions which
unexpectedly and unintentionally results in personal injury, property
damage or advertising liability during the policy period” and stated
that “[a]ll such exposure to substantially the same general conditions
existing at or emanating from one premises location shall be deemed
one occurrence.” Michigan Chemical Corp. v. American Home
Assurance Co., 728 F.2d at 378. Another set of policies similarly
provided that with respect to property damage, an occurrence was “1)
an accident or 2) continuous or repeated exposure to conditions which
results in injury to or destruction of tangible property, including
consequential loss resulting therefrom, while this agreement is in
effect” and that “[a]ll damages arising out of such exposure to
substantially the same general conditions shall be considered as arising
out of one occurrence.” (Emphases omitted.) Michigan Chemical
Corp. v. American Home Assurance Co., 728 F.2d at 378.
     The policies in Roman Catholic Diocese of Joliet, 292 Ill. App.
3d at 449-50 likewise stated that an occurrence was “an accident or
happening or event or a continuous or repeated exposure to
conditions which unexpectedly and unintentionally results [sic] in
personal injury, or damage to property during the policy period.” The
policies also provided that all exposure to substantially the same
general conditions existing at or emanating from one location was to
be deemed one occurrence.
     Under the policy considered in Illinois Central R.R. Co., 317 Ill.
App. 3d at 745, the term occurrence meant “one or more accidents or
disasters and/or series of accidents or disasters arising out of or
resulting from one event.” In Illinois National Insurance Co. v.
Szczepkowicz, 185 Ill. App. 3d at 1094, “one accident” (which was
viewed as synonymous with occurrence) was defined as “all bodily
injury and property damage resulting from continuous or repeated

                                 -14-
exposure to substantially the same conditions.” Camp Point’s policy
stated simply that with regard to professional services, an occurrence
was “an error, negligent omission or negligent act or a series of
related errors, negligent omissions or negligent acts, regardless of the
number of claims or claimants.” Village of Camp Point, 219 Ill. App.
3d at 88. In none of these six cases was the term occurrence found to
be ambiguous.
      As our discussion has indicated, all of the foregoing cases
ultimately concluded that covered damages resulted from multiple
occurrences. There have been a few decisions, however, in which the
damages were found to be the product of a single occurrence. The
first Illinois appellate court case to have so found is United States
Gypsum Co. v. Admiral Insurance Co., 268 Ill. App. 3d 598 (1994),
a declaratory judgment action brought by United States Gypsum
Company (Gypsum) against its insurers to obtain coverage for actions
filed against it based on its manufacture and sale of building material
containing asbestos. The building material consisted primarily of
ceiling finishing plaster which was installed at various locations at
various times between 1937 and the 1970s. United States Gypsum Co.
v. Admiral Insurance Co., 268 Ill. App. 3d at 607-08.
      Among the issues raised in the case was whether the actions
giving rise to Gypsum’s liability constituted multiple occurrences for
purposes of calculating the deductible limits under certain of
Gypsum’s liability policies. Those policies contained language similar
to that used in the cases we have already discussed. One set of policies
provided that “[t]he deductible amount shall apply ‘per occurrence’ to
the Bodily Injury and Property Damage combined regardless of the
number of persons or organizations seeking damages” and that “[a]ll
damages arising out of a common defect, condition or cause shall be
considered as arising out of one occurrence.” United States Gypsum
Co. v. Admiral Insurance Co., 268 Ill. App. 3d at 648. A second set
of policies stated that “ ‘occurrence’ shall mean sudden or continuous
or repeated exposure to any condition resulting in *** injury or
destruction during the policy period” and that “all such injury or
destruction caused by continuous or repeated exposure to
substantially the same condition shall be deemed to result from one
occurrence.” United States Gypsum Co. v. Admiral Insurance Co.,
268 Ill. App. 3d at 647.

                                 -15-
     Looking first to this policy language, taking into account the
cause theory for determining the number of occurrences under a
liability policy, and considering the factual circumstances giving rise
to Gypsum’s liability, the appellate court concluded that the operative
cause was “the continuing process of the manufacture and sale of
asbestos-containing products.” United States Gypsum Co. v. Admiral
Insurance Co., 268 Ill. App. 3d at 649. Central to the court’s analysis
was the nature of the product involved. “Generally,” the court
observed, it has been held that “ ‘if the continuous production and sale
of an intrinsically harmful product results in similar kinds of injury or
property damage, then all such injury or property damage results from
a common occurrence.’ [Citations.]” United States Gypsum Co. v.
Admiral Insurance Co., 268 Ill. App. 3d at 650. The court further
took into account the nature of Gypsum’s involvement in the process
that gave rise to the damages for which indemnification was sought.
Citing Mason v. Home Insurance, 177 Ill. App. 3d at 459-60, for the
proposition that the type of activity in which the insured engages
should be considered in determining the number of occurrences, the
court rejected the argument that each installation of asbestos-
containing building material should be viewed as a separate
occurrence. In the court’s view:
          “[i]t would be unwise and without support in case law to
          determine that each installation of the asbestos-containing
          products constituted a separate occurrence when Gypsum’s
          liability is predicated on its involvement in the manufacture
          and sale of the products rather than the installation of the
          products.” United States Gypsum Co. v. Admiral Insurance
          Co., 268 Ill. App. 3d at 651.
     The analysis employed in United States Gypsum Co. v. Admiral
Insurance Co., 268 Ill. App. 3d 598, is consistent with that followed
by the United States District Court for the Northern District of Illinois
in Household Manufacturing, Inc. v. Liberty Mutual Insurance Co.,
1987 U.S. Dist. LEXIS 1008 (N.D. Ill. February 11, 1987), mod. on
other grounds, 1987 U.S. Dist. LEXIS 10837 (N.D. Ill. November
16, 1987). Household Manufacturing, Inc. involved a dispute over an
insurance company’s alleged failure to indemnify a company for
damages arising from the company’s manufacture and sale of a plastic
hot-cold pressure plumbing system (the Quest system) for residential

                                  -16-
use. The Quest system was manufactured and then supplied to
plumbing contractors throughout the United States on a continuous
basis over multiple years. Numerous lawsuits ensued, claiming that the
system was defective and had caused property damage. Those
lawsuits were brought primarily on theories of strict liability, tort,
breach of warranty and negligence. Household Manufacturing, 1987
U.S. Dist. LEXIS 1008, *1.
     The principal issue in the case was whether the claims for which
coverage was sought constituted one occurrence or multiple
occurrences within the meaning of the applicable liability policies. The
company which manufactured and sold the system argued that there
was only a single occurrence, that it was therefore subject to only one
“stop loss” amount, and that all sums included within ratable incurred
losses above that single stop loss amount must be indemnified by its
insurer up to the policy limits.
     The policies in question defined occurrence as “an accident,
including continuous or repeated exposure to conditions, which results
in ‘bodily injury’ or ‘property damage’ neither expected nor intended
from the standpoint of the ‘insured.’ ” Household Manufacturing,
1987 U.S. Dist. LEXIS 1008, *5-6. The polices further provided that
for purposes of determining liability, “all ‘personal injury’ and all
‘property damage’ arising out of continuous or repeated exposure to
substantially the same general conditions *** shall be considered as
arising out of one occurrence.” Household Manufacturing, 1987 U.S.
Dist. LEXIS 1008, *6.
     In applying these provisions to the particular facts of the case in
accordance with the cause theory, the court agreed with the
manufacturer’s position. The court observed that it had to rely on
“ ‘the ordinary meaning of the words [in the policy], in relation to the
business risk to be insured against,’ ” namely, “ ‘protection from
liability from a defective product produced in a continuous flow of
production and intended for widespread use *** ending in a multitude
of consumer products in many hands.’ [Citation.]” Household
Manufacturing, 1987 U.S. Dist. LEXIS 1008, *12. According to the
court, the manufacturer in this case sold its system on a mass basis,
“and it was anticipated that any defects in the system would affect a
large number of persons in the chain of distribution.” Household
Manufacturing, 1987 U.S. Dist. LEXIS 1008, *12. The continuous

                                 -17-
and repeated manufacture and sale of an allegedly defective product
on a mass basis is what gave rise to the manufacturer’s liability and to
its right to recover under the policies and therefore constituted the
single, unitary cause of the claims against the manufacturer.
Accordingly, the court concluded, there was but one occurrence
within the meaning of the insurance policies, and the insurer was
obligated to indemnify the manufacturer for all ratable incurred losses
over the stop loss amount. Numerous cases from other jurisdictions
involving the sale of defective products by an insured manufacturer
were cited by the court in support of this holding. See Household
Manufacturing, 1987 U.S. Dist. LEXIS 1008, *14-20.
      A single cause was also found in Aetna Casualty & Surety Co. v.
O’Rourke Bros., Inc., 333 Ill. App. 3d 871 (2002), a declaratory
judgment action to settle insurance coverage questions arising from
claims filed against the insured, a consumer electronics distributor,
based on its scheme to defraud costumers in connection with the sale
and financing of satellite systems. Under the applicable liability policy,
the insurer’s obligation to indemnify the distributor for covered
damages was subject to a $10,000 retained limit. The retained limit,
which operated like a deductible, applied to “any one occurrence or
offense.” An occurrence, in turn, was defined as “an accident,
including continuous or repeated exposure to substantially the same
general harmful conditions.” Aetna Casualty & Surety Co. v.
O’Rourke Bros., Inc., 333 Ill. App. 3d at 881. Applying the analysis
set forth in United States Gypsum Co. v. Admiral Insurance Co., 268
Ill. App. 3d 598, the court held that the cause of the claims for which
indemnification was sought was the distributor’s fraudulent sales
campaign. In the court’s view, that campaign was not a series of
separate and discrete events, but rather a single, continuing process.
The court therefore concluded that there was only one occurrence for
purposes of the liability policy. Accordingly, the retained limit amount
did not apply to each individual claim. Instead, it was to be applied
only once to all of the claims combined. Aetna Casualty & Surety Co.
v. O’Rourke Bros., Inc., 333 Ill. App. 3d at 882.2

  2
   Single occurrences were also involved in two additional appellate court
cases, Outboard Marine Corp. v. Liberty Mutual Insurance Co., 283 Ill.
App. 3d 630 (1996) , which pertained to the ongoing pollution of Waukegan

                                  -18-
      Applying the foregoing body of case law, the appellate court in
the case before us today concluded that where each asserted loss is the
result of a separate and intervening human act, whether negligent or
intentional, or each act increased the insured’s exposure to liability,
Illinois law will deem each such loss to have arisen from a separate
occurrence within the meaning of liability policies containing language
similar to that used in the policies issued to Nicor by the London
Insurers. 362 Ill. App. 3d at 753. By contrast, where the damages for
which coverage is sought resulted from the manufacture and sale of
defective products or a fraudulent sales scheme, the loss will be found
to have emanated from a single cause and there will be but one
occurrence for purposes of the applicable policies. 362 Ill. App. 3d
752.
      The parties to this case have not asserted that the losses incurred
by Nicor were the result of the manufacture and sale of defective
products or a fraudulent sales scheme. The appellate court therefore
concluded that cases such as Household Manufacturing, Inc. v.
Liberty Mutual Insurance Co., 1987 U.S. Dist. LEXIS 1008 (N.D. Ill.
February 11, 1987); United States Gypsum Co. v. Admiral Insurance
Co., 268 Ill. App. 3d 598 (1994), and Aetna Casualty & Surety Co.
v. O’Rourke Bros., Inc., 333 Ill. App. 3d 871 (2002), were
distinguishable. In the appellate court’s view, this dispute fell instead
under the line of cases beginning with Mason v. Home Insurance Co.
of Illinois, 177 Ill. App. 3d 454 (1988), where each asserted loss was
the result of a separate and intervening human act or each act



Harbor caused by the insured’s manufacturing plant, and Missouri Pacific
R.R. Co. v. International Insurance Co., 288 Ill. App. 3d 69 (1997),
involving claims by the insured’s employees for on-the-job hearing loss and
asbestos exposure. In neither of those cases, however, was the issue of single
or multiple occurrences raised in the same context that it is presented here.
The principal issue they addressed is how coverage should be allocated
among different policies covering different periods of time. See also Hartford
Casualty Insurance Co. v. Medical Protective Co. of Fort Wayne, Indiana,
266 Ill. App. 3d 781 (1994) (doctor’s negligence which took place during
multiple policy periods constituted single occurrence and policies covering
the separate periods could not be stacked).


                                    -19-
increased the insured’s exposure to liability. Based on that line of
cases, applied in the factual context of this case and in light of the
language used in the pertinent policies, the appellate court held that
each of the 195 mercury spills subject to the London Insurers’ policies
constituted a separate occurrence. 362 Ill. App. 3d at 754-56.
      We believe that the appellate court’s analysis was sound. The
circumstances of this case place it squarely within Mason v. Home
Insurance Co. of Illinois, 177 Ill. App. 3d 454 (1988), and its
progeny. The liability for which Nicor sought indemnification from the
London Insurers did not arise from any inherent defect in the old-
styled gas regulators or the manner in which they were installed in
customers’ homes. Nor did it derive from any systemwide policy or
procedure regarding the methodology employed for removing the
regulators between 1961 and 1978, the period covered by the London
Insurers’ policies. To the contrary, the record indicates that the
methods employed by Nicor for removing the regulators during the
period in question were the same as those ultimately approved by the
court after the Attorney General filed suit against the company in the
year 2000.
      Liability was incurred only when mercury happened to spill as an
old-style regulator was being replaced with one of the new mercury-
free units. Such spills were extremely rare. Impermissibly high levels
of mercury contamination were discovered in one-half of 1% of the
homes where physical inspections were undertaken.3 The spills had no
common cause. Mercury escaped from the regulators under a variety
of circumstances, including unique physical circumstances in particular
homes which required technicians to tilt gas meters in order to remove
them. One spill was reported to have resulted when the Nicor
technician accidently stumbled or tripped. Sometimes technicians were


    3
     Nicor contends that the true incidence of mercury contamination is
actually unknown because early spills may have evaporated and left no
traces by the time testing was undertaken. Aside from being entirely
speculative, this observation is irrelevant. The purpose of this litigation is to
resolve responsibility for costs incurred in detecting and remediating mercury
contamination that was still present in customers’ homes. If a spill had
evaporated and left no traces, there could be no dispute regarding who should
bear the burden of remediation costs, for no remediation was necessary.

                                     -20-
careless and neglected to follow Nicor’s safe mercury-handling
procedures. In addition, the spills occurred at different times over a
17-year period in the case of the spills subject to the London Insurers’
policies. No temporal or geographical pattern to these spills was
established, and no claim was made that any particular technician or
group of technicians was responsible for the spills. The technicians did
not even share a common employer. Some were apparently Nicor
employees while others worked for the company’s subcontractors. To
say that each of the 195 spills emanated from a single cause would,
under these circumstances, be completely untenable.
      As we have previously discussed, the relevant policies in effect
between 1961 and 1976 define an occurrence as “one happening,” or
a series of happenings arising out of or due to “one event,” while the
policies for 1976 through 1978 speak of “an accident” or “event” or
“continuous or repeated exposure to conditions which result in [injury,
death or physical damage to or destruction of property].” Nothing in
these definitions is materially different from the definitions employed
in the various Illinois appellate court decisions to which the appellate
court looked for guidance, and they are no more ambiguous in this
case than they were in those cases. Giving the words of the policies
their plain and ordinary meaning, as we must, the 195 spills were not
“one happening,” they were not derived from “one event, “ and they
were not all part of “an accident.” Moreover, they cannot be
characterized as involving “continuous or repeated exposure to
conditions which result in [injury, death or physical damage to or
destruction of property].” They were sporadic, not part of an
uninterrupted process, and in no instance evident in the record was
any customer’s home ever subject to more than one exposure to
mercury contamination. The exposure therefore could not have been
“repeated.”
      In arguing that the damages attributable to the spills should be
characterized as haven arisen from a single cause, Nicor asserts that
its “liability was not tied to any individual spills.” Rather, it attributes
its liability to the overall costs of investigating and remediating the
spills in response to the legal actions filed against it, costs which it
contends are indivisible. This argument is without merit. The legal
action is not the operative “happening,” “event,” or “accident” giving
rise to liability under the policies. The spills are, and the damages

                                   -21-
associated with the 195 specific spills covered by the polices can be
and have been specifically identified.4
      There is likewise no merit to Nicor’s contention that the spills
should be viewed as the result of a single cause because the individual
claims of its customers were allowed to proceed as a class action and
the attorney general’s action sought redress for all of the spills at the
same time in the same proceeding. Consolidation of individual claims
and the request for comprehensive remedial action in the underlying
litigation relate to questions of litigation efficiency. They have no
bearing whatever on the issue of how many occurrences there were
under the terms of the applicable insurance policies.
      We also reject Nicor’s argument that an interpretation of the
policies to find 195 separate occurrences rather than one single
occurrence will somehow deny it the benefit of its bargain. Because
the damages attributable to each of the 195 contaminated homes was
conceded to be less than the applicable deductibles, the determination
that each spill was a separate occurrence and therefore subject to a
separate deductible does mean that Nicor will be able to collect
nothing from the London Insurers. An insurance contract, however,
is not a guarantee of indemnification for every dollar of every loss.
      Through deductibles or self insured retentions, a policy holder
may elect to absorb part of the risk for any covered loss in exchange
for reduced premiums. That is precisely what Nicor did here. There is
nothing in the policies themselves or in the circumstances surrounding
the purchase of those policies to suggest in any way that the parties
specifically contemplated that if situations like this one arose, the
losses would be consolidated for purposes of determining the
applicable deductible. In light of the policy language as interpreted in
Illinois, Nicor knew or should have known that such claims would be
viewed as individual occurrences. By electing deductibles in the


  4
   We further note, parenthetically, that if the remediation order entered in
the underlying legal proceedings were deemed to be the cause of Nicor’s
damages, the London Insurers’ policies would not even be involved. The
coverage provided by those policies ended in 1978. The legal proceedings
against Nicor were not resolved and the remediation order was not entered
until the year 2000.

                                    -22-
amounts it did, Nicor voluntarily agreed to assume the risk of
absorbing individual claims of the magnitude involved here. What it
apparently misjudged is the total number of such individual claims it
might have to meet at once. While that is unfortunate from Nicor’s
point of view, the company was not an unsophisticated consumer who
was unfairly taken advantage of. It is a major business corporation
with substantial experience and formidable bargaining power. No
principle of public policy authorizes courts to relieve such entities of
the consequences of business calculations merely because those
calculations ultimately prove to be erroneous.
     BorgWarner, Inc., who appears in this case as a friend of the
court, concedes that current Illinois case law supports the appellate
court’s determination that each of the 195 spills constituted a separate
occurrence. It also rejects the contention that making each spill
subject to a separate deductible would deny Nicor the benefit of its
bargain. In its view, however, the way in which the cause theory has
been applied in Illinois has become mired in inconsistency and
unpredictability. It argues that this court should address this problem
by refocusing on established principles of contractual construction and
acknowledge that the term occurrence is ambiguous on its face and
under the facts of this case.
     We reject BorgWarner, Inc.’s position for three reasons. First, in
making its argument, BorgWarner suggests that insurance policy
provisions should be found ambiguous whenever there is no clear
answer on the face of the policy itself as to how those provisions
should be applied in a particular factual setting. This approach is not
supported by the law of Illinois, as the discussion of insurance policy
ambiguity set forth earlier in this opinion shows. Second, as we have
previously noted, Illinois courts have expressly considered whether
policy provisions such as those at issue in this case were ambiguous
and held that they are not. BorgWarner cites no authority from this
state to support a contrary position. Third, wholly aside from these
considerations, neither Nicor nor the London Insurers take the
position that the term occurrence is ambiguous. This court has held
that we will not address issues raised by an amicus where, as here,
those issues have not previously been raised by the parties themselves.
In re Parentage of M.J., 203 Ill. 2d 526, 542 (2003).


                                 -23-
     As with BorgWarner, John Crane, Inc., the other amicus in this
case, agrees that the appellate court was correct in concluding that the
195 mercury spills were separate occurrences under the controlling
policies. It also believes, however, that the cause theory, as presently
applied, has yielded inconsistent results. The remedy it proposes is
similar to BorgWarner’s in that it would have courts refocus their
analysis on the language used in the policies. The difference is that
unlike BorgWarner, John Crane sees no inherent ambiguity in the term
occurrence. Instead, it contends that in evaluating how many
occurrences there are for purposes of coverage under a liability policy,
courts should look first to whether the policy contains a “unifying
directive,” that is, language that purports to aggregate multiple
injuries and claims arising at different times and places into a single
occurrence. Under John Crane’s analysis, the presence of such a
unifying directive would not necessarily result in a finding of a single
occurrence. In the absence of a unifying directive, however, it would
hold that “a single, omnibus occurrence result is never appropriate.”
     We express no view on the merits of John Crane’s proposal for
the simple reason that the rule the company suggests is not necessary
to the disposition of this case. A “no unitary directive rule” would
have no bearing on the policies issued by the London Insurers for the
period between November of 1976 and 1978 because those policies
did contain a unifying directive. As John Crane argues, as the
appellate court found, and as we affirm today, the damages attendant
to the mercury spills nevertheless constituted separate occurrences
within the meaning of those policies.
     While the polices in effect between 1961 and November of 1976
lacked a unifying directive, having a “no unitary directive rule” would
not affect our construction of those policies either. The existing
analytical framework as developed by the appellate court in Mason v.
Home Insurance Co. of Illinois, 177 Ill. App. 3d 454 (1988), and the
cases that followed already make clear that the dispute before us here
involved multiple occurrences rather than one omnibus occurrence.
Whether we had a “no unitary directive rule” or not, the result in this
case would therefore remain unchanged. Accordingly, any discussion
of the merits of such a rule would be purely academic.
     Finally, both BorgWarner and John Crane argue that the
inconsistency they see in the current approach can be remedied by

                                 -24-
adopting a different formulation for applying the cause test than has
been used by our appellate court. BorgWarner argues for a “cause of
injury test.” John Crane speaks of a “last causal element” test.
Although their nomenclature differs, these approaches are premised
on a common idea, namely, that the immediate event giving rise to the
injury should be deemed the cause of an occurrence.
      As a preliminary matter, we are unconvinced that the existing
approach has created the inconsistency amici claim. The principal
example of inconsistent results cited by John Crane involves Mason
v. Home Insurance Co. of Illinois, 177 Ill. App. 3d 454 (1988), and
United States Gypsum Co. v. Admiral Insurance Co., 268 Ill. App. 3d
598 (1994), both of which we have discussed in this opinion at length.
According to John Crane, the contaminated patty melts in Mason
were no different than the building material containing asbestos in
United States Gypsum and the two cases should therefore have
reached the same result. Instead, as we have noted, Mason was
deemed to have involved multiple occurrences, while United States
Gypsum found a single occurrence.
      Assuming, for the sake of argument, that Mason’s patty melts are
analogous to the asbestos in United States Gypsum’s building
materials, we do not believe that these decisions are at odds. There is
a critical distinction between the cases which John Crane overlooks:
the predicate for the policy holders’ liability. The insured party in
Mason was the restaurant owner whose liability was based on his sale
of the contaminated food to the consumers who patronized his
restaurant. In United States Gypsum, the insured party manufactured
and distributed the building materials, but did not sell them to
consumers or install them in the end-users’ structures. That was done
by others. Accordingly, the insured’s liability was based on its
manufacture and distribution of the materials, not their sale to
consumers and ultimate installation As the appellate court in this case
recognized, the analysis in U.S. Gypsum suggests that if the insured’s
liability had been based on installation of the materials rather than their
manufacture, each installation would have been a separate occurrence,
just as each sale of a patty melt was a separate occurrence in Mason.
362 Ill. App. 3d at 742. The cases are therefore not incompatible.
      In any event, as the London Insurers aptly observe, adopting the
alternate formulations proffered by the amici would not alter the result

                                   -25-
in this case. Under any approach to the cause theory, the mercury
spills would be separate occurrences under the policies they issued to
Nicor. Because we perceive no inconsistency in the current approach
to the question as developed by our appellate court and because the
alternative analytical framework advanced by the amici would not
alter our disposition of the present case, we respectfully decline the
amici’s request to use this litigation to recast the law.

                            CONCLUSION
      For the foregoing reasons, the appellate court acted correctly
when it rejected the circuit court’s conclusion that the liability
incurred by Nicor was the result of a single occurrence, reversed the
circuit court’s judgment, and remanded for further proceedings. Under
the liability policies issued to Nicor by the London Insurers between
1961 and 1978, each of the 195 spills did constitute a separate
occurrence, as the appellate court properly held. The appellate court’s
judgment is therefore affirmed.

                                                             Affirmed.

     JUSTICE BURKE took no part in the consideration or decision
of this case.




                                 -26-
