                              In the

United States Court of Appeals
               For the Seventh Circuit

No. 12-1888

D AVID F URRY and D IANE N YE,
                                                Plaintiffs-Appellants,
                                  v.

U NITED S TATES OF A MERICA,
                                                 Defendant-Appellee.


             Appeal from the United States District Court
        for the Northern District of Illinois, Eastern Division.
           No. 1:08-cv-6138—Blanche M. Manning, Judge.



   A RGUED S EPTEMBER 26, 2012—D ECIDED M ARCH 13, 2013




 Before E ASTERBROOK, Chief Judge, and W OOD and
W ILLIAMS, Circuit Judges.
  W ILLIAMS, Circuit Judge. In this Federal Tort Claims
Act case, David Furry and Diane Nye allege that
Ronald Williams, a substitute letter carrier for the
United States Postal Service, negligently caused a vehicle
collision that resulted in substantial injuries. Furry and
Nye, who were in the station wagon that made con-
tact with Williams’s postal truck, did not see Williams’s
2                                               No. 12-1888

vehicle before the accident or observe the collision. At
the bench trial, they argued that the vehicle damage,
Williams’s lack of credibility, and his flight from
the scene of the accident all proved that Williams
acted negligently. The district court declined to find
that Williams breached his duty of ordinary care, and
we conclude that the court’s factual finding on this
issue was not clearly erroneous. To prevail, Furry and
Nye needed to show by a preponderance of the evi-
dence that Williams initiated the contact between the
vehicles. And because they relied on speculation
rather than evidence, they failed to meet their burden.
We affirm.


                   I. BACKGROUND
   On the afternoon of May 15, 2007, David Furry,
Diane Nye, and their daughter were traveling south-
bound on Grove Avenue, a one-way street in Berwyn,
Illinois. Furry was driving the family’s 1978 Ford
LTD Country Squire station wagon. It was raining
heavily that afternoon and visibility was limited. At the
same time, Ronald Williams, a recently hired substitute
letter carrier for the United States Postal Service (“USPS”),
was sitting in a postal truck that was parallel parked on
the right side of Grove Avenue at a slight angle with
the front of the truck sticking out. Williams had just
visited the home of a friend and, in violation of USPS
rules, was away from his designated route.
  As Furry’s station wagon passed Williams’s postal
truck, the two vehicles collided. The quarter panel and
No. 12-1888                                              3

bumper on the right rear of Furry’s car made contact
with the left front bumper of the postal truck. The impact
pushed Furry against the driver’s side window and
Nye forward against her seatbelt. Furry and Nye
did not see the postal truck before the impact, nor did
they see the collision.
  After the accident, Furry and Nye examined the dam-
age to their station wagon, which suffered minimal
damage to the right rear quarter panel and the right side
of the rear bumper, which came off its mount. Williams
pulled the postal truck away from the curb, drove several
car lengths away, parked, and exited the truck. Furry
asked Williams to call the police because Furry and Nye
did not have cell phones. Williams offered Furry five
hundred dollars to not report the accident and to give
Williams an opportunity to leave the scene. While
Furry searched for straps to lift the station wagon’s
bumper off the ground, Nye talked to Williams, who
said, “Oh, my God. Oh, my God. Oh, this is great.
I’m going to get fired. I have to get the rest of this mail
delivered. I’m sorry.” After Nye asked Williams for his
information and told him to call the police, Williams
then stated again that he was sorry and said, “Oh, my
God. Oh, my God. I am going to get fired. I have to get
this mail delivered or I’ll be fired.” Nye again told him
to call the police, but Williams walked back to the postal
truck, drove away from the scene, and returned to
his postal route. Nye wrote down the number of
Williams’s vehicle.
  After searching for Williams for fifteen to twenty min-
utes, Furry and Nye returned to their home. Ninety
4                                            No. 12-1888

minutes after the collision, Furry called the Berwyn
Police Department to report the accident. Officer James
Tadrowski met Furry and Nye at their residence. They
told the police officer their version of events—that Wil-
liams hit their vehicle when he pulled out of his parking
space, that they talked to Williams and asked for his
information, and that he would not give it to them
because he was afraid he would lose his job if the
crash were reported. Officer Tadrowski returned to the
scene of the collision but did not see any evidence of
a crash. He did not take any paint scrapings, photo-
graphs, or measurements of the vehicles. Later that
day, he located Williams and questioned him at the
Furry/Nye residence with Lee Junious, a USPS customer
service supervisor. Williams denied any involvement in
the collision and claimed that he had never seen Furry
or Nye before. Williams resigned from USPS the
following day.
  After exhausting their administrative remedies, Furry
and Nye sued the United States under the Federal Tort
Claims Act (“FTCA”), alleging that Williams’s negligence
caused them $45 million in damages. The court held a
bench trial in July and August 2011. The plaintiffs
testified that they believed that Williams caused the
accident by driving the postal truck out of its parking
space into their station wagon. Officer Tadrowski also
testified about the damage to the vehicles and his inter-
actions with the plaintiffs and Williams, but the
district court did not find him “qualified to opine as to
which vehicle struck the other.” The plaintiffs did not
offer any expert testimony on the cause of the collision.
No. 12-1888                                                 5

  Even though both parties subpoenaed Williams, he
did not appear at the bench trial. After the plaintiffs
declined to compel Williams’s attendance, the parties
agreed that he would testify by deposition. In his dep-
osition testimony, Williams’s account of the incident
differed from Furry’s and Nye’s in several ways.
Most importantly, he claimed that the postal truck
was stationary at the time of the collision and that he
had not yet begun to exit the parking space when the
station wagon clipped his vehicle. When the plaintiffs’
counsel asked Williams to reconcile his assertion that
the postal truck was not moving with the fact that
the back end of Furry’s car came into contact with
the postal truck, Williams responded that he had no ex-
planation and that it was “mystical.” In addition, Williams
testified that Furry accepted the offer of five hundred
dollars, while the plaintiffs do not mention any accep-
tance. Finally, Williams asserted that he did not speak
with Nye at the scene.
   At the conclusion of the bench trial, the court took
the matter under advisement. The parties subsequently
filed proposed findings of fact and memoranda of law.
   In its findings of fact, the court credited the plaintiffs’
testimony that “the station wagon impacted the postal
vehicle,” but it noted that because they did not see the
postal truck or the collision, “their belief [that Williams
initiated the collision] is not based on any first-hand
observation of movement by the postal vehicle, but rather
is based on the fact that they felt an impact.”
 The court stated that it “had no opportunity to gauge
Williams’ credibility for itself because the plaintiffs
6                                               No. 12-1888

chose not to ask the court to compel his attendance at
trial and decided, instead, to rely on his deposition testi-
mony.” The court then explained that even if it were
to assume that Williams lacked credibility and to
consider the plaintiffs’ testimony not rebutted, their
“testimony establishe[d] only that their station wagon
and the postal vehicle collided, not which vehicle was
responsible for the collision.” The court found that
there were other possible causes of the accident, in-
cluding Furry’s vehicle sideswiping the postal truck
or hydroplaning (recall that there was heavy rain at the
time) into the postal truck unbeknownst to the plain-
tiffs. And because, according to the parties, USPS could
have fired Williams for either being involved in
any accident, regardless of fault, or being away from
his designated route, the court would not infer that
negligence was the only possible reason Williams left
the scene.
  The district court entered judgment in favor of
the United States, finding that the plaintiffs failed to
meet their burden of proof on breach of duty by a pre-
ponderance of the evidence because they offered only
“sheer speculation”—not evidence or expert opinion—to
support their position that the damage to their vehicle
and the postal truck conclusively proved that Williams
initiated the contact. Furry and Nye appeal.


                      II. ANALYSIS
 In the FTCA, 28 U.S.C. §§ 1346(b)(1) & 2671-80, Congress
waived the United States’s sovereign immunity for
No. 12-1888                                                7

suits brought by persons injured by the negligence of
federal employees acting within the scope of their em-
ployment. Emp’rs Ins. of Wausau v. United States, 27
F.3d 245, 247 (7th Cir. 1994). The “law of the place where
the act or omission occurred” governs FTCA claims,
28 U.S.C. § 1346(b)(1), so we rely on Illinois law here.
To succeed on a negligence claim in Illinois, a plaintiff
“must allege and prove that the defendant owed a duty
to the plaintiff, that defendant breached that duty, and
that the breach was the proximate cause of the
plaintiff’s injuries.” First Springfield Bank & Trust v.
Galman, 720 N.E.2d 1068, 1071 (Ill. 1999). The parties
agree that Williams had “a duty to exercise reasonable
care in the operation of his vehicle and to have his
vehicle under such control as [would] enable him to
avoid collision with other vehicles or pedestrians.” Moran
v. Gatz, 62 N.E.2d 443, 444 (Ill. 1945). So the issues pre-
sented for resolution at the bench trial were breach,
proximate cause, and damages.


  A. Clear Error Standard of Review
  In an appeal from a bench trial, we review the district
court’s findings of fact and applications of law to those
findings for clear error. Trs. of Chi. Painters & Decorators
Fund v. Royal Int’l Drywall & Decorating, Inc., 493 F.3d 782,
785 (7th Cir. 2007). We will find clear error when we
are “left with the definite and firm conviction that a
mistake has been committed.” Anderson v. City of
Bessemer City, 470 U.S. 564, 573 (1985). And “[w]e may
have such a conviction if ‘the trial judge’s interpretation
8                                              No. 12-1888

of the facts is implausible, illogical, internally incon-
sistent or contradicted by documentary or other extrinsic
evidence.’ ” EEOC v. Sears Roebuck & Co., 839 F.2d 302,
309 (7th Cir. 1988) (quoting Ratliff v. City of Milwaukee,
795 F.3d 612, 617 (7th Cir. 1986)).
  Ordinarily, breach and proximate cause are questions
of fact reviewed for clear error. Swearingen v. Momentive
Specialty Chems., Inc., 662 F.3d 969, 972 (7th Cir. 2011)
(applying Illinois law). But when “there is no material
issue regarding the matter or only one conclusion is
clearly evident,” breach and proximate cause become
questions of law reviewed de novo. Williams v. Univ. of
Chi. Hosps., 688 N.E.2d 130, 134 (1997); accord Adams v.
N. Ill. Gas Co., 809 N.E.2d 1248, 1257 (Ill. 2004) (“the
issues of breach and proximate cause are factual matters
for a jury to decide, provided there is a genuine issue
of material fact regarding those issues”) (internal
citation omitted).
  On appeal, Furry and Nye argue that this court
should treat proximate cause as a question of law
because there is only one possible cause of the car
accident—Williams driving the postal truck into their
station wagon. We assume that the appellants intended
to argue that we should treat breach of duty as a question
of law because the district court entered judgment
based on the plaintiffs’ failure to prove breach and stated
that it “need not address the issues of proximate cause
and damages.”
  The appellants’ argument is unpersuasive. Because
they offered no eyewitness testimony regarding the
No. 12-1888                                              9

cause of the accident, “the facts of the collision[] had to
be inferred from the circumstances.” Miller v. Pillsbury
Co., 211 N.E.2d 733, 734 (Ill. 1965). And the circum-
stances here require some consideration of the context of
the crash, the condition of the vehicles, the angle and
degree of impact, the vehicle’s traveling speed, and the
effect of the weather. The appellants present what they
consider to be a “commonsense” analysis of the damage
to conclude that the only way the right rear quarter
panel and right rear bumper of their car and the left
front bumper of Williams’s truck would have suffered
the type of damage they did would have been if
Williams pulled out of his parking space and hit their
station wagon. But even if their analysis offers a
plausible explanation for the collision, it by no means
necessarily excludes all other possible causes, including
those suggested by the district court. And for this
reason, breach remains a question of fact reviewed for
clear error.


 B. The District Court’s Breach Finding Was Not
    Erroneous
  Having determined that breach is a question of fact
here, we turn now to the appellants’ substantive argu-
ments. First is their argument that the damage could
only have resulted from Williams’s negligence, an argu-
ment we have already called into question. The appel-
lants offered no expert testimony on accident reconstruc-
tion to explain why their account was likely more ac-
curate than another scenario in which Williams did
10                                              No. 12-1888

not breach his duty of ordinary care. Mere speculation,
which is all they offer, is not sufficient to meet their
burden of proof.
  The appellants next argue that Williams’s testimony
was so incredible that it proved their version of events.
This is also unpersuasive. The district court declined
to find that Williams lacked credibility because it did
not have an opportunity to observe his demeanor.
On appellate review, we defer to the district court’s
credibility determinations “for only the trial judge can
be aware of the variations in demeanor and tone of
voice that bear so heavily on the listener’s understanding
of and belief in what is said.” Anderson, 470 U.S. at
575. And “when a trial judge’s finding is based on his
decision to credit the testimony of one of two or more
witnesses, each of whom has told a coherent and
facially plausible story that is not contradicted by
extrinsic evidence, that finding, if not internally incon-
sistent, can virtually never be clear error.” Id. at 575-76;
see also Mucha v. King, 792 F.2d 602, 605-06 (7th Cir.
1986) (“[T]he main reason for appellate deference to the
findings of fact made by the trial court is not the
appellate court’s lack of access to the materials for
decision but that its main responsibility is to maintain
the uniformity and coherence of the law . . . .”).
   Although the district court declined to determine Wil-
liams’s credibility, the lack of a determination does not
matter here. The appellants want us to conclude that
Williams is not credible because he initially lied about
his involvement and fled the scene of the accident, but
No. 12-1888                                             11

that behavior does not necessitate a finding that every-
thing Williams says lacks credibility. Neither does his
inability to reconcile his account of the accident with
the vehicle damage, as the appellants argue. As we have
discussed, Furry and Nye’s version of events requires
accident reconstruction testimony; the district court
did not err by declining to hold Williams’s inability
to provide that testimony against him. But most impor-
tantly, as the district court noted, even if it excluded
Williams’s testimony as not credible, the appellants did
not satisfy their burden of proof by a preponderance of
the evidence. See NLRB v. Luois A. Weiss Mem’l Hosp.,
172 F.3d 432, 446 (7th Cir. 1999) (“An absence of
evidence does not cut in favor of the one who bears
the burden of proof on an issue.”). Furry and Nye
testified that they did not witness the collision or even
see the postal truck before the impact. And because
they offered no evidence to either support their specula-
tion or to discount other possible causes of the collision,
they failed to meet their burden of proof.
  Finally, the appellants argue that the district court
could have inferred Williams’s negligence from the fact
that he fled the scene of the collision. See Peterson v.
Henning, 452 N.E.2d 135, 138 (Ill. App. Ct. 1983) (“A
defendant’s flight from the scene of the accident can be
interpreted as an admission of his negligence for if he
were ‘guilt free’ it is reasonable to assume he would stop
to ascertain the nature of the accident or the extent of
the victim’s injuries.”). But the appellants suggested
alternate reasons for the flight: Nye testified that
Williams stated several times that he needed to return
12                                                  No. 12-1888

to his route or he would be fired. And Nye also told
Officer Tradowski that Williams did not want to
provide them with his information because he was
afraid that he would lose his job if the collision were
reported. Furthermore, Williams left the scene after
stopping and having the opportunity to observe that
no one was visibly injured and that there was only
minor damage to the station wagon. Leaving under
these circumstances does not necessarily signal culp-
ability, and given the other possible explanations for
Williams’s flight from the scene, the district court did
not clearly err by declining to consider it evidence of
negligence.1



1
  We note that the appellants’ recitation of the facts in their
appellate brief suggests other potential evidence of negligence.
First is the statement that after the collision, “He [Williams]
said he was sorry for hitting them.” As we noted at oral argu-
ment, the district court did not address this potential admis-
sion by Williams.
  In their post-trial supplemental statement of facts below,
Furry and Nye said that Williams said “he was sorry.” Both of
these statements appear to be based on Nye’s testimony.
She first testified that Williams said “I’m sorry.” But at a later
point in the trial, she later identified Williams as “the one
that came out and said: I’m sorry for hitting you.” Furry and
Nye did not argue that this latter statement is evidence of
Williams’s breach either at trial (and they did not include it
in their post-trial proposed findings of fact or argue it in their
memorandum of law) or in their appellate briefs.
                                                    (continued...)
No. 12-1888                                                    13

  Ultimately, the appellants’ arguments on breach rest
on sheer speculation. Faced with the lack of evidence
to either support the appellants’ beliefs or discount al-
ternate explanations not associated with Williams’s
breach of ordinary care, the district court did not err
by finding that the appellants failed to meet their
burden of proof.


1
   (...continued)
   It is possible that Nye inadvertently attached the “for hitting
you” explanation to Williams’s “I’m sorry.” Or it could be
that those were Williams’s exact words. But the appellants
never discussed the potential importance of the statement. So
despite the presence of what a factfinder could interpret as
an admission of breach of duty and the fact that the dis-
trict court did not make a factual finding about whether
Williams admitted culpability, we will not remand this case
on this issue because Furry and Nye never attempted to
advance this argument. See Economy Folding Box Corp. v. Anchor
Frozen Foods Corp., 515 F.3d 718, 720-21 (7th Cir. 2008) (“It is
not the court’s responsibility to research the law and construct
the parties’ arguments for them.”); Robyns v. Reliance Standard
Life Ins. Co., 130 F.3d 1231, 1238 (7th Cir. 1997) (“The well-
established rule in this Circuit is that a plaintiff waives the
right to argue an issue on appeal if she fails to raise the
issue before a lower court.”); Nemmers v. United States, 795
F.2d 628, 633 (7th Cir. 1986) (in a bench trial, Federal Rule of
Civil Procedure 52(a) “requires the court to make findings of
fact and conclusions of law on all material, disputed issues
(emphasis added)). Similarly, because Furry and Nye only
argued that Williams’s offer to pay Furry five hundred dollars
was evidence of Williams’s lack of credibility, we will not
remand due to lack of a factual finding about whether that
offer was evidence of an admission.
14                                          No. 12-1888

                 III. CONCLUSION
  For the reasons above, we A FFIRM the judgment of the
district court.




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