In the
 United States Court of Appeals
              For the Seventh Circuit
                         ____________

No. 06-1985
JOSE A. AGUIRRE and
MARIA L. AGUIRRE,
                                           Plaintiffs-Appellants,
                                v.

TURNER CONSTRUCTION COMPANY,
BARTON-MALOW COMPANY, KENNY
CONSTRUCTION COMPANY, and TBMK,
                                          Defendants-Appellees.
                         ____________
           Appeal from the United States District Court
      for the Northern District of Illinois, Eastern Division.
            No. 05 C 515—Suzanne B. Conlon, Judge.
                         ____________
 ARGUED NOVEMBER 6, 2006—DECIDED SEPTEMBER 7, 2007
                   ____________


 Before RIPPLE, WILLIAMS, and SYKES, Circuit Judges.
  SYKES, Circuit Judge. Jose Aguirre was injured when he
fell from a scaffold while working for a masonry subcon-
tractor on the Soldier Field renovation project in Chicago.
Aguirre and his wife brought negligence claims based on
section 414 of the Restatement (Second) of Torts and res
ipsa loquitur against the general contractors in charge of
the renovation. Aguirre maintains the defendants owed
him a duty of reasonable care based on their extensive
oversight of all project safety. The district court granted
2                                               No. 06-1985

summary judgment for the defendants after concluding
they had not retained sufficient control over the subcon-
tractor’s work to give rise to any duty of care toward
Aguirre or supply a basis for liability on a res ipsa loquitur
theory. Because we conclude that these holdings are
inconsistent with the requirements of Illinois negligence
law, we reverse.


                      I. Background
  Jose Aguirre was injured when he fell from a scaffold
while working as a bricklayer on the renovation of Soldier
Field in Chicago. Aguirre was an employee of A.L.L.
Masonry (“A.L.L.”), one of numerous subcontractors
working on the renovation project. The project was over-
seen by the defendants, collectively known as the joint
venture TBMK. Aguirre maintains that his fall was the
result of design and/or construction defects in the scaf-
fold. He and his wife brought negligence and loss of con-
sortium claims against the defendants based on section
414 of the Restatement (Second) of Torts, which permits
direct liability against a general contractor who retains
sufficient control over a subcontractor, and on res ipsa
loquitur, which permits circumstantial evidence of liabil-
ity against a defendant in control of the instrumentality
of the injury. The defendants moved for summary judg-
ment on the ground that they, as the general contractors,
owed no duty under either theory to Aguirre, an employee
of a subcontractor.
  Discovery proceeded to determine the extent of control
TBMK retained over A.L.L.’s work. This discovery demon-
strated that although the contract between TBMK and
A.L.L. stated that A.L.L. remained “solely responsible
for the safety of [its] employees,” TBMK also played an
active part in overseeing the safety of the renovation
project. For example, TBMK promulgated an extensive
No. 06-1985                                                3

125-page safety program that all subcontractors were
required to follow, and it hired a safety coordinator and
other personnel to oversee that program. TBMK also held
monthly safety meetings, required subcontractors to hold
regular safety meetings that TBMK could monitor, and
required subcontractors to prepare their own site-specific
safety programs. TBMK personnel walked the work site
daily to monitor compliance with these safety require-
ments. The safety coordinator and his employees had and
sometimes exercised the authority to halt any subcon-
tractor work being performed in an unsafe manner.
  TBMK’s safety program, which is part of its contract
with A.L.L., included 23 rules specifically pertaining to
the erection of scaffolding. Those rules imposed both
design requirements, such as guardrail and plank specifi-
cations, and safety precautions, such as regular inspec-
tion and fall protection. The district court found that
although “TBMK was not required to inspect all of the
scaffolding, [it] did do so.” The scaffold from which Aguirre
fell had been specifically altered from the standard design
based on an irregularity in the area where the work was
being performed. Although no TBMK employee inspected
the scaffold prior to Aguirre’s fall, TBMK had worked
with A.L.L. to create and approve its alternate design.
   The district court granted summary judgment for the
defendants on both the section 414 and res ipsa loquitur
theories of liability. First, the court stated that under
Illinois law res ipsa loquitur requires a defendant to be
in exclusive control of the instrumentality of the injury.
Thus, the court concluded, this theory could not be used
because A.L.L. employees constructed the scaffold from
which Aguirre fell. Turning to section 414 of the Restate-
ment, the court determined that although TBMK exercised
extensive authority over work site safety, TBMK could
not be liable because “the contract between TBMK and
A.L.L. provided that A.L.L. controlled operative work
4                                                No. 06-1985

details. . . . [and] its workers’ safety.” The court noted that
“A.L.L. was contractually required to comply with TBMK’s
safety program, design its own safety program tailored
to TBMK’s safety standards, and employ personnel to en-
sure compliance.” Thus, the court held, no duty of care
could exist “because [TBMK] did not have control of the
incidental details of A.L.L.’s work or its workers’ safety.”
The plaintiffs appealed.


                      II. Discussion
  We review de novo a district court’s grant of summary
judgment, viewing the evidence in the light most favor-
able to the nonmoving party. Healy v. City of Chicago, 

, 738 (7th Cir. 2006). Summary judgment is
appropriate when “the pleadings, depositions, answers
to interrogatories, and admissions on file, together with
the affidavits, if any, show that there is no genuine
issue as to any material fact and that the moving party
is entitled to judgment as a matter of law.” FED. R. CIV.
P. 56(c). When we must decide an unsettled question of
state law while sitting in diversity, as we are here, we are
obligated to determine how the highest court of that state
would rule. Hinc v. Lime-O-Sol Co., 

, 720 (7th
Cir. 2004). We review de novo a district court’s interpreta-
tion of the content of state law. 

Regina
Coll. v. Russell, 

(1991)).


A. Section 414 Liability
    The Restatement (Second) of Torts, section 414 states:
     One who entrusts work to an independent contractor,
     but who retains the control of any part of the work, is
     subject to liability for physical harm to others for
     whose safety the employer owes a duty to exercise
No. 06-1985                                                 5

    reasonable care, which is caused by his failure to
    exercise his control with reasonable care.
The “retained control” theory of negligence liability
described in section 414 was adopted by the Illinois
Supreme Court in Larson v. Commonwealth Edison Co.,

(Ill. 1965). However, some confusion has
arisen recently among Illinois intermediate appellate
courts regarding whether section 414 states a theory of
vicarious liability or direct liability. See, e.g., Cochran v.
George Sollitt Const. Co., 

, 361 (Ill. App. Ct.
2005). Although the Illinois Supreme Court has yet to
lend its guidance on this issue, we are confident it
would interpret section 414 in accordance with its plain
language and accompanying commentary, which clearly
state a theory of direct liability for a general contractor’s
own negligence, not a basis for imposing vicarious liabil-
ity on a general contractor for the negligence of a subcon-
tractor.
  The bulk of the existing confusion stems from comment
a to section 414, which states:
    If the employer of an independent contractor retains
    control over the operative detail of doing any part of
    the work, he is subject to liability for the negligence of
    the employees of the contractor engaged therein, under
    the rules of that part of the law of Agency which deals
    with the relation of master and servant. The employer
    may, however, retain a control less than that which
    is necessary to subject him to liability as master. He
    may retain only the power to direct the order in which
    the work shall be done, or to forbid its being done in a
    manner likely to be dangerous to himself or others.
    Such a supervisory control may not subject him to
    liability under the principles of Agency, but he may
    be liable under the rule stated in this Section unless
    he exercises his supervisory control with reasonable
6                                               No. 06-1985

    care so as to prevent the work which he has ordered to
    be done from causing injury to others.
Some courts, including the district court in this case, have
mistakenly read this comment as first laying out when
section 414 applies, see, e.g., 

(“As comment a to section 414 clarifies, the general
contractor, by retaining control over the operative details
of its subcontractor’s work, may become vicariously liable
for the subcontractor’s negligence . . . .”), then explaining
that no liability can exist if the general contractor
“retain[s] only the power to direct the order in which the
work shall be done, or to forbid its being done in a manner
likely to be dangerous to himself or others.” See Aguirre v.
Turner Constr. Co., 

at *3 (N.D. Ill. Mar.
9, 2006).
   Properly read, comment a does just the opposite. The
first sentence does not explain the scope of section 414,
but rather merely refers to the principles of vicarious
liability within the Restatement of Agency. Where the
level of retained control gives rise to a master-servant
relationship, the master will be liable for the torts of his
servant; this is no-fault vicarious liability and it is based
on the principles of agency law, not negligence law. When
comment a continues with “[t]he employer may, however,
retain a control less than that which is necessary to
subject him to liability as master” and “may retain only
the power to direct the order in which the work shall be
done, or to forbid its being done in a manner likely to be
dangerous to himself or others,” the commentators are
demarcating the boundary between agency law (which if
applicable imposes vicarious liability) and the negligence
principles encompassed in section 414.
  As the next sentence of the comment explains, section
414 takes over where agency law ends by providing a
theory of direct liability based on the existence of a duty of
No. 06-1985                                                      7

reasonable care. That duty is triggered when the em-
ployer—usually a general contractor—has retained
supervisory control over the independent contractor
without retaining control over all operative details of a
project. As comment b explains, the rule stated in section
414 “is usually, though not exclusively, applicable when
a principal contractor entrusts a part of the work to
subcontractors, but himself or through a foreman super-
intends the entire job.” Comment b elaborates that negli-
gence liability arises in this situation if the general
contractor “knows or by the exercise of reasonable care
should know that the subcontractors’ work is being [done
dangerously], and has the opportunity to prevent it by
exercising the power of control which he has retained
in himself.” Liability also arises if the general contractor
“knows or should know that the subcontractors have
carelessly done their work in such a way as to create a
dangerous condition, and fails to exercise reasonable
care either to remedy it himself or by the exercise of his
control to cause the subcontractor to do so.”
  Proceeding on the understanding that section 414 states
a theory of direct liability based on a general contractor’s
failure to exercise reasonable care, whether TBMK re-
tained a level of control sufficient to give rise to a duty to
exercise reasonable care is a question of law.1 See Rangel
v. Brookhaven Constructors, Inc., 

, 176 (Ill.
App. Ct. 1999). As comment c to section 414 explains:
    In order for the rule stated in this Section to apply, the
    employer must have retained at least some degree of
    control over the manner in which the work is done. It
    is not enough that he has merely a general right to


1
  We note that at oral argument the Aguirres acknowledged that
their section 414 claim is a direct liability claim; they abandoned
any vicarious liability claim.
8                                                No. 06-1985

    order the work stopped or resumed, to inspect its
    progress or to receive reports, to make suggestions or
    recommendations which need not necessarily be
    followed, or to prescribe alterations and deviations.
    Such a general right is usually reserved to employers,
    but it does not mean that the contractor is controlled
    as to his methods of work, or as to operative detail.
    There must be such a retention of a right of supervi-
    sion that the contractor is not entirely free to do the
    work in his own way.
Illinois courts have held that “an employer need only
retain the control of any part of the work in order to be
subject to liability for a failure to exercise his control with
reasonable care.” Brooks v. Midwest Grain Prods. of Ill.,
Inc., 

, 155 (Ill. App. Ct. 2000) (emphasis
added).
  In determining whether that level of control has been
retained, Illinois courts ask whether the principal merely
retained general oversight of work progress and safety or
actually engaged in detailed supervision and/or control of
subcontractors’ methods and means of performing work.
See, e.g., Ross v. Dae Julie, Inc., 

, 72 (Ill.
App. Ct. 2003) (“[A] general right to ensure that safety
precautions are observed and that work is done in a safe
manner will not impose liability on the general contractor
unless the evidence shows that the general contractor
retained control over the means and methods of the
independent contractor’s work.”).
  The most prominent and closely comparable case in
which a retained control duty of care was found to exist is
Bokodi v. Foster Wheeler Robbins, Inc., 

(Ill.
App. Ct. 2000). In Bokodi, the Illinois appellate court
found the existence of a duty based on the general contrac-
tor’s extensive oversight of safety on a large-scale construc-
tion project. Specifically, the general contractor provided
No. 06-1985                                              9

29 safety measures and procedures that subcontractors
were required to follow, employed safety personnel to
monitor the site for compliance with its safety guidelines,
gave its own employees broad powers to halt any subcon-
tractor work based on a perception of an unsafe working
environment, required subcontractors to conduct safety
training meetings that the general contractor’s employees
could monitor, and required subcontractors to participate
in its own safety programs. 

  Although TBMK attempts to diminish Bokodi’s force by
pointing to a number of recent cases that have found no
duty under section 414, the facts of those cases are easily
distinguishable. For example, in Martens v. MCL Construc-
tion Corp. the general contractor’s employees had no
authority to stop deficient work of subcontractors,

, 491 (Ill. App. Ct. 2004); in Kotecki v.
Walsh Construction Co. the general contractor engaged in
no oversight whatsoever of the work the plaintiff per-
formed for the subcontractor, 

, 778 (Ill.
App. Ct. 2002); and in Rangel the general contractor
promulgated no specific safety rules for the work in

. By contrast, a duty was found
to exist in Moorehead v. Mustang Construction Co., a case
more like Bokodi in that the general contractor had a
detailed safety program in place and regularly monitored
the subcontractor’s work site for compliance with its own
safety standards. 

(Ill. App. Ct. 2004).
Indeed, even in rejecting the existence of a duty, the
Martens court noted that “if a defendant’s safety program
sufficiently affected a contractor’s means and methods of
doing its work, then such program could bring the defen-
dant within the ambit of the retained control 

. Accordingly, nothing in these cases
calls into question the application of Bokodi here.
  The evidence of TBMK’s extensive safety oversight is
arguably even stronger than that of the general contrac-
10                                              No. 06-1985

tors in Bokodi and other similar Illinois cases. The record
establishes that TBMK required A.L.L. to follow 23 rules
specific to scaffold construction, that TBMK employees
regularly walked the site and could require A.L.L. to
correct any deficiencies observed in scaffolds, that TBMK
inspected many of A.L.L.’s scaffolds, and notably, that
TBMK imposed specific alternative design requirements on
the scaffold from which Aguirre fell. These undisputed
facts clearly establish that TBMK’s safety program
sufficiently affected A.L.L.’s means and methods of doing
its work so as to give rise to a duty of reasonable care. In
holding to the contrary, the district court emphasized that
TBMK did not control all “the incidental details of A.L.L’s
work or its workers’ safety.” As we have explained, how-
ever, this kind of overarching retention of operative control
described in comment a is necessary only when the claim
asserted is one for vicarious liability under agency law. By
contrast, section 414 describes the general contractor’s
duty of reasonable care that arises under negligence law
when “the [sub]contractor is not entirely free to do the
work in his own way,” see comment c, which was clearly
the case with regard to A.L.L.’s scaffolding.
  The district court’s attempt to distinguish Bokodi on
contractual grounds is similarly inapposite. Although the
contract between TBMK and A.L.L. placed A.L.L. in
control of the operative details of its work, the same was
true in 

. Nonetheless, as the
district court recognized, the Bokodi court concluded that
this contractual term was contravened by the “great
lengths [the general contractor undertook] to enforce the
safety standards at the work site.” 

precautions taken by TBMK—specific safety and design
requirements, regular monitoring with authority to halt
unsafe work—evince the same level of control over the
details of A.L.L.’s scaffolding work, regardless of the
contractual language to the contrary. The contractual
No. 06-1985                                              11

assignment of oversight of employee safety to A.L.L. does
not control here for the same reason it did not in Bokodi,
i.e., because TBMK’s extensive safety oversight and
requirements affected the means and methods by which
A.L.L. sought to ensure the safety of its own employees.
  Based on the remarkable similarities between Bokodi
and this case, we conclude that TBMK retained sufficient
control over the safety of scaffolding design and construc-
tion to give rise to a duty of reasonable care under section
414 of the Restatement. Of course, this holding does not
mean the defendants are liable for Aguirre’s injuries;
that remains a question for the jury.


B. Res Ipsa Loquitur
  The doctrine of res ipsa loquitur allows for “proof of
negligence by circumstantial evidence when the direct
evidence concerning cause of injury is primarily within the
knowledge and control of the defendant.” Kolakowski v.
Voris, 

, 400 (Ill. App. Ct. 1980) (internal
citation omitted). Illinois law provides that to prevail
under res ipsa loquitur, a plaintiff must demonstrate he
was injured: (1) in an occurrence that would not have
happened in the absence of negligence; and (2) by an
instrumentality under the management or control of the
defendant. Dyback v. Weber, 

(Ill. 1986).
Contrary to the district court’s assertion, the Illinois
Supreme Court has concluded that it is not necessary to
establish the defendant’s exclusive control over the instru-
mentality for the doctrine to apply. See Lynch v. Precision
Mach. Shop, Ltd., 

, 573 (Ill. 1982). Rather,
“the key question is whether the probable cause [of the
injury] is one which defendant was under a duty to the
plaintiff to anticipate or guard against.” 

has alleged that his fall occurred when the
scaffold collapsed due to negligent design or construction.
12                                             No. 06-1985

As we have discussed, there is sufficient evidence in this
record that TBMK retained some control over both the
design and construction of A.L.L.’s scaffolding. Lynch held
that joint control of the sort TBMK and A.L.L. shared
over the scaffolding design and construction is not a bar
to the application of res ipsa loquitur in such a circum-
stance. 

Accordingly, there is a genuine issue of
material fact as to both elements of res ipsa loquitur, and
the plaintiffs may proceed on that theory as well.
  For the foregoing reasons, the district court’s grant
of summary judgment is REVERSED, and the case is
REMANDED for further proceedings consistent with this
opinion.

A true Copy:
      Teste:

                       ________________________________
                       Clerk of the United States Court of
                         Appeals for the Seventh Circuit




                   USCA-02-C-0072—9-7-07