dissenting. This case, in which an escalator came to a sudden stop causing a passenger to fall and sustain injuries, presents a classic example of the type of case to which the doctrine of res ipsa loquitur (“the thing speaks for itself’) has commonly been applied. Accidents involving elevators and escalators have consistently been identified as appropriate for application of the doctrine, because they are accidents for which direct evidence of negligence is frequently unavailable, but that, based upon common experience, would not ordinarily occur in the absence of negligence. See Barwick v. United States, 923 F.2d 885 (D.C. Cir. 1991); Colmenares Vivas v. Sun Alliance Ins. Co., 807 F.2d 1102 (1st Cir. 1986); Ebanks v. New York City Transit Authority, 70 N.Y.2d 621, 512 N.E.2d 297, 518 N.Y.S.2d 776 (1987); see also 19 Am. Jur. 3d Proof of Facts 43, § 21 (1993); 4 F. Harper, F. James & O. Gray, Torts (2d Ed. 1986) § 19.6, pp. 33-36 n.13.
Nevertheless, the majority finds application of the doctrine to be precluded in this case merely because an expert witness produced by the plaintiff testified that, although he was not permitted to inspect the escalator involved until nearly five years after the accident occurred, he found the escalator to have been installed properly and to be free of design defects, and that he did not know what caused the escalator to stop suddenly. Notwithstanding this testimony, the trial court should have instructed the juiy on the doctrine of res ipsa loquitur in accordance with the plaintiffs request to charge.
In Giles v. New Haven, 228 Conn. 441, 636 A.2d 1335 (1994), this court reviewed the circumstances that must exist in order to entitle a plaintiff to a jury instruction on the doctrine of res ipsa loquitur. Traditionally, application of the doctrine required that three conditions be satisfied: “(1) [t]he situation, condition, or apparatus causing the injury must be such that in the ordinary *180course of events no injury would result unless from a careless construction, inspection or user[;] (2) [b]oth inspection and user must have been at the time of the injury in the control of the party charged with neglect[;] [and] (3) [t]he injurious occurrence or condition must have happened irrespective of any voluntary action at the time by the party injured. ” (Internal quotation marks omitted.) Id., 446. In Giles, this court modified the parameters of the second and third conditions, but did not have the occasion to review the first condition because the parties agreed that it had been satisfied.
In Giles, we expanded the sécond and third prongs of the doctrine of res ipsa loquitur. With regard to the second prong, we recognized that exclusive control was not necessary as long as “the jury could reasonably find that the defendant’s control was sufficient to warrant an inference that the defendant was more likely responsible for the incident than someone else . . . .’’Id.,450. With regard to the third prong, we held that contributory negligence on the part of the plaintiff would not bar the application of the doctrine. Despite these modifications of the doctrine, which were intended to bring the doctrine of res ipsa loquitur into the twenty-first century, the majority narrowly construes the first prong in this case and, in doing so, ignores our precedent and its logical extension.
The majority concludes that the trial court’s refusal to instruct the jury on the doctrine of res ipsa loquitur was appropriate because, in its view, the first condition had not been satisfied due to the plaintiffs failure to produce evidence that the accident was of the sort that ordinarily would not occur in the absence of negligence. In order to satisfy the first condition, however, it is not necessary that any evidence whatsoever be produced to establish the latter proposition. Instead, the condition is intended to draw upon ordinary past experience. “Where common experience has demonstrated that no *181injury would ordinarily result from a situation, condition or apparatus unless there was careless construction, inspection or user . . . common sense permits an inference of negligence from proof of the injury and the physical agency inflicting it . . . Lowman v. Housing Authority, 150 Conn. 665, 670, 192 A.2d 883 (1963).
Whether application of the doctrine of res ipsa loquitur is appropriate under given circumstances is a question of law. Giles v. New Haven, supra, 228 Conn. 447. Yet, in making that decision, courts are not without guidance. Where the balance is a close one, this court’s decision in Motiejaitis v. Johnson, 117 Conn. 631, 169 A. 606 (1933), is instructive. In Motiejaitis, this court stated that, “[i]f, upon the evidence, reasonable [persons] might disagree as to whether or not the conditions upon which the application of the doctrine depends were present in the case, it must be submitted to the jury. ... If they find that the conditions do exist but no definite cause or causes of the accident are proven, it is for them to determine whether, in view of the circumstances of the accident including those involved in the application of the doctrine and all the relevant facts, it is more probable than not that the injury was due to the negligence of the defendant.” Id., 635; see also 2 Restatement (Second), Torts § 328D (1965) (while “[i]t is the function of the court to determine whether the inference may reasonably be drawn by the jury . . . [i]t is the function of the jury to determine whether the inference is to be drawn in any case where different conclusions may reasonably be reached”).
Where evidence is introduced to rebut the inference of negligence, application of the doctrine is not necessarily precluded. “When the defendant . . . offers evidence that the event was not due to his negligence, the inference which arises ... is not necessarily overthrown.” 2 Restatement (Second), supra, § 328D, com*182ment (n). “The inference of negligence remains in the case and will sustain a finding of negligence, even though there be countervailing evidence, unless such adverse evidence so conclusively shows nonnegligence of the defendant that reasonable minds, acting fairly, could not find [the defendant] negligent.” Witort v. United States Rubber Co., 3 Conn. Cir. Ct. 690, 695-96 (1966). In other words, the evidence should be of such a character as to undermine the inference on which the doctrine of res ipsa loquitur is based.1 If the evidence is not of such a character, the case should go to the jury, with the benefit of the res ipsa loquitur instruction, for the jury to decide in light of the evidence whether to draw the inference. This result is consistent with Motiejaitis.
Indeed, this approach to conflicting evidence and inferences has been applied to situations in which the plaintiff introduced expert testimony. “[I]t is quite generally agreed that the introduction of some evidence which tends to show specific acts of negligence on the part of the defendant, but which does not purport to furnish a full and complete explanation of the occurrence, does not destroy the inferences which are consistent with the evidence, and so does not deprive the plaintiff of the benefit of res ipsa loquitur. ” W. Prosser & W. Keeton, Torts (5th Ed. 1984) § 40, p. 260; see also Kranda v. Houser-Norborg Medical Corp., 419 N.E.2d 1024, 1042 (Ind. App. 1981); Mobil Chemical Co. v. Bell, 517 S.W.2d 245, 254-55 (Tex. 1974). Furthermore, “the *183plaintiff does not lose fthe doctrine’s] benefits by introducing some evidence of specific negligence which does not establish clearly and definitely the precise cause of the injury, or, as it is sometimes more concisely phrased, that the plaintiffs unsuccessful attempt to prove specific negligence will not deprive him of the inferences or presumptions otherwise available under res ipsa loquitur.” Annot., 33 A.L.R.2d 791, 795 (1954). In other words, only when the evidence makes the inference unreasonable is the inference logically precluded.
In the present case, the majority finds application of the doctrine to be inappropriate because the plaintiff produced no direct evidence of negligence, but produced some evidence tending to rebut the inference of negligence. Specifically, the majority claims that the plaintiff was not entitled to the instruction because the plaintiffs own expert, Michael Shanok, an engineer, testified on direct examination that his inspection revealed that the escalator had been installed properly and was free of design defects, and testified on cross-examination that the escalator had stopped because of a jiggled wire or a “gremlin” in the system. The majority concludes that, in light of that testimony, the inference of negligence could not survive. In my view, that conclusion is inappropriate in light of the evidence presented.
Shanok testified that “[i]n my opinion, it is far more probable that the escalator was not caused to stop by someone else, but the escalator stopped on its own for no outward reason . . . .’’He further testified that his inspection of the escalator, nearly five years after the accident occurred, revealed no malfunctioning parts or defects. He stated that his findings were “that the escalator appeared to have been installed properly” and that “[t]he design was correct.” Following his inspection, Shanok formed an opinion as to what might have caused the accident. He stated that there remained “only the safety interlock devices as a possible reason*184able cause of an escalator stopping for no apparent reason.” Specifically, Shanok stated that “[i]t’s my opinion that in all probability either one of these interlock devices malfunctioned, or there was a loose wire attached to any one of the electrical devices in the control circuit that came loose from vibration.” When asked to identify the cause of the accident more specifically, Shanok answered that “[t]here is no way of knowing because after the . . . incident the wrong escalator was inspected [by the defendant or its agent] so that the evidence was gone.” When asked to explain his opinion as to a loose wire possibly having caused the accident, Shanok replied, “I have no idea if that happened. There is no way of knowing.”
On cross-examination, Shanok was questioned about his responses given during a deposition regarding the cause of the accident. Defense counsel asked Shanok if he remembered “giving this answer . . . when asked about what caused the escalator to stop: ‘There are a number of different things on an escalator that can stop it. And it could be any one of them. It would be conjecture to say that one or the other was at fault.’ Do you remember giving that answer?” Shanok replied, “[t]hat’s correct.” He also testified that he remembered stating during the deposition that apossible cause of the accident could have been a “gremlin” in the escalator system. Finally, when asked if he remembered being asked in the deposition about whether in his opinion the defendant had been negligent in its maintenance of the escalator, Shanok responded that he remembered that his reply to the question was that “[t]here is in terms of what caused this incident, it is unfound and untraceable.”
In my view, Shanok’s testimony is not of a character that should preclude application of the doctrine of res ipsa loquitur. The evidence is not such that, as a matter of law, it must be said that a reasonable person could *185not conclude, in light of the evidence, that an inference of negligence drawn from the circumstances of the accident has been foreclosed. First, the evidence did not demonstrate that a factor other than negligence caused the accident at issue here to occur. Second, the evidence produced was speculative and inconclusive, and is best summed up in Shanok’s own words: “There is no way of knowing.” The fact is that Shanok was not provided with an opportunity to examine the escalator until five years after the accident occurred. His testimony consisted of hypothetical commentary about what might have caused the accident. Shanok admitted that he did not know what caused the accident. He did not conclusively rule out negligence as the cause of the accident, but, rather, speculated that in all probability the accident was caused by either a loose wire or a “gremlin” in the escalator’s electrical system. Shanok did not testify that in the past accidents of the type at issue here have occurred in the absence of negligence. The plaintiff is not required to eliminate with certainty all other possible causes or inferences. “ ‘It is enough that the facts proved reasonably permit the conclusion that [the defendant’s] negligence is the more probable explanation.’ ” Giles v. New Haven, supra, 228 Conn. 448.
Furthermore, the possible causes that Shanok identified for the escalator’s sudden stop were not of a sort that ordinarily would occur even if all reasonable precautions had been taken. With respect to the possibility that a loose wire had caused the accident, Shanok explained that sometimes a wire within the electrical system could be jiggled loose, causing it temporarily to lose contact, and thereby cause the escalator to stop. The second possible cause that he identified was a “gremlin” in the system, that being something that goes wrong that is difficult to trace. Even if Shanok were correct, he did not testify that the defendant could not have prevented these conditions. The majority, how*186ever, with no basis in the evidence, speculates that this is the case.
I would hold that the plaintiff was entitled to a jury instruction on the doctrine of res ipsa loquitur and I would affirm the judgment of the Appellate Court that the plaintiff was entitled to a new trial.
Accordingly, I dissent.
In Malvicini v. Stratfield Motor Hotel, Inc., 206 Conn. 439, 443-44, 538 A.2d 690 (1988), the defendants argued “that the weight of the evidence contradicting the plaintiffs claims rebuts this first condition and precludes the invocation of res ipsa loquitur.” This court, however, held that because “[the defendant’s] argument ... is actually an attack upon the plaintiffs version of the incident, and does not relate to whether, as a matter of common experience, it can be said that a shower does not ordinarily turn suddenly hot in the absence of negligence,” the first condition for the application of res ipsa loquitur had not been satisfied. Id., 444.