
    Vincent Amatulli, Jr., an Infant, by His Mother and Natural Guardian, Lorraine Amatulli, et al., Respondents-Appellants, v Delhi Construction Corporation, Defendant; Philip Susi et al., Appellants-Respondents; Sea-spray Sharkline, Inc., et al., Respondents. (And Third- and Fourth-Party Actions.)
    Argued January 3, 1991;
    decided April 2, 1991
    
      POINTS OF COUNSEL
    
      Michael Conforti for respondents-appellants.
    
      
      Jane E. Motyka for Philip Susi and another, appellants-respondents.
    
      Patti F. Potash for Brothers Three, Inc., appellant-respondent.
    
      Barbara D. Goldberg for Seaspray Sharkline, Inc., respondent.
   OPINION OF THE COURT

Alexander, J.

We again are confronted with questions concerning the liability of the manufacturer, distributor and owner of a swimming pool for injuries sustained by a plaintiff who executed a headfirst dive into the pool. The pool was four feet deep, and was designed, manufactured and marketed for installation above ground. However, it was installed with two feet of the pool sunken into the ground and a deck built partially around the pool which gave it the appearance of an in-ground pool.

On September 11, 1983, Vincent Amatulli, Jr., who was then 16 years old, sustained serious injuries when he executed a headfirst dive into this swimming pool which had been installed at the home of Janet and Philip Susi. Vincent, who was a guest at a pool party held at the Susis’ contends that prior to diving into this pool, he was aware that the pool appeared shallow around its sides, but that the bottom of the pool seemed to slope downward toward the center such that he gauged the depth of the water toward the center where he aimed his dive to be about six feet. Consequently he executed his dive at a 45 degree angle so as to reach what appeared to be the deep part of the pool. He was wrong, the depth was only four feet and he struck his head on the bottom. Vincent testified at his deposition that he was an experienced swimmer and diver, having received advanced swimming and diving instructions. He had not used this pool previously but had swum in a similar four-foot pool at the Susis’ former residence.

This action was commenced by Vincent and his mother against the owners of the pool, Janet and Philip Susi, the pool manufacturer Seaspray Sharkline, Inc. (Seaspray), the retail-distributor of the pool, Brothers Three, Inc. (Brothers) and Delhi Construction Corporation, of which the Susis were principals, and which initially was believed to have installed the pool. Various cross claims and counterclaims were asserted by and among the parties and Woodsman Construction Company and its principals, the actual installers of the pool, were joined as parties defendant.

The Appellate Division, with one Justice dissenting, affirmed Supreme Court’s grant of summary judgment to Seaspray, dismissing the complaint and all cross claims against it. That court also affirmed the denial of the cross motions for summary judgment of the defendants Susi, Brothers and Woodsman. Plaintiffs appeal and the Susis, and Brothers cross-appeal, pursuant to leave granted by the Appellate Division, which has certified to us the question "[wjas * * * the decision and order of this court dated December 13, 1989, properly made?” We now affirm the Appellate Division order and answer thé certified question in the affirmative.

I

Both the Appellate Division and Supreme Court concluded that inasmuch as the pool, when manufactured and distributed by Seaspray, was safe for its intended use as an above-ground recreational swimming pool, Seaspray could not be liable for the plaintiff's injuries under a theory of strict products liability.

Plaintiffs argue however that the pool was defectively designed in that an aqua-colored vinyl liner was used which deceptively created the impression of a greater depth to the water than actually existed. Additionally, they contend that Seaspray failed to adequately warn against the dangers of diving into the pool and failed to specifically instruct and warn against in-ground installation of the pool notwithstanding that Seaspray knew or should have known that it was common practice to install these above-ground pools in the ground.

Plaintiffs argue further that the Appellate Division erred in concluding that the in-ground installation of the pool was a material alteration that created a new potential danger within the meaning of Robinson v Reed-Prentice Div. (49 NY2d 471). They argue also that the Appellate Division erred in concluding that Seaspray had no duty to warn against diving because the danger of diving into a four-foot above-ground pool was open and obvious.

The Susis and Brothers contend on their cross appeals that the conduct of Vincent, an experienced swimmer and diver, in executing a headfirst dive into what he knew or should have known with the exercise of reasonable care was a shallow pool, constituted the sole proximate cause of his injuries. Thus, under Smith v Stark (67 NY2d 693) and Howard v Poseidon Pools (72 NY2d 972) their motion for summary judgment dismissing the complaint should have been granted. Additionally, they argue that summary judgment should have been denied to Seaspray because material issues of fact were raised as to the defective design of the pool’s filtration system and the aqua-colored vinyl liner, the adequacy of the warnings as to the dangers of diving into the shallow pool and whether installing two feet of the pool into the ground and building a partial deck around it constituted a material alteration of the pool and a proximate cause of Vincent’s injuries. Brothers also contend that their motion for summary judgment dismissing the complaint should have been granted, especially in view of the grant of Seaspray’s motion for summary judgment. For the reasons set forth below, these arguments are unavailing.

II

We note that this case comes to us on motions for summary judgment, addressed to the complaint and cross claims, and thus the Court’s role is limited to issue finding, not issue resolving (see, CPLR 3212; 4 Weinstein-Korn-Miller, NY Civ Prac ¶ 3212.01; Friends of Animals v Associated Fur Mfrs., 46 NY2d 1065; Zuckerman v City of New York, 49 NY2d 557).

Seaspray’s undisputed proof established that the pool in question was designed and sold to be used as an above-ground pool for recreational swimming and that detailed instructions as to its intended above-ground installation were provided. Clear and explicit warnings as to the shallowness of the pool and against diving and jumping into the pool were also provided. Contrary to Seaspray’s instructions, however, the pool was installed with two feet of its four-foot depth below ground level, and a deck built partially around it thus creating the impression that it was an in-ground pool, capable of being used in a manner and for a purpose different from that intended by the manufacturer. As the Appellate Division aptly observed, had the pool been properly installed as an above-ground pool, its depth would have been readily apparent and would itself have served as an evident warning against diving (156 AD2d 500, 501). Plaintiff’s expert himself opined that the in-ground installation of the pool helped to disguise and camouflage the actual depth of the water (156 AD2d, at 503).

A manufacturer who places into the stream of commerce a defective product which causes injury may be liable for such injury, (see, Codling v Paglia, 32 NY2d 330). A defect in a product may consist of a mistake in manufacturing, an improper design or the inadequacy or absence of warnings for the use of the product (see, Codling v Paglia, 32 NY2d 330, supra; Micallef v Miehle Co., 39 NY2d 376; Torrogrossa v Towmotor Co., 44 NY2d 709). For there to be a recovery for injuries or damages occasioned by a defective product, however, that defect must have been a substantial factor in bringing about the injury or damage and additionally, among other things, at the time of the occurrence, the product must have been used for the purpose and in the manner normally intended or in a manner reasonably foreseeable (Codling v Paglia, supra). It is well settled that a manufacturer, who has designed and produced a safe product, will not be liable for injuries resulting from substantial alterations or modifications of the product by a third party which render the product defective or otherwise unsafe (see, Robinson v Reed-Prentice Div., 49 NY2d 471, supra). Moreover, in such circumstances, we have concluded that "[principles of foreseeability * * * are inapposite where a third party affirmatively abuses a product by consciously bypassing built-in safety features.” (Id., at 480.)

Installing the pool in the ground and surrounding it with a deck transformed its configuration in such manner as to obscure its four-foot depth, which would have been readily apparent as a warning against diving had the pool been installed above ground. Thus this transformation of the pool’s configuration created a new potential danger not attributable to the manufacturer or the pool’s design (see, Robinson v Reed-Prentice Div., 49 NY2d 471, 480-481, supra).

Plaintiffs argue, however, that Seaspray knew or should have known that pools of this type were commonly being installed in-ground. Therefore, there should have been explicit warnings against such foreseeable installation and more adequate warnings against diving affixed to the pool itself. Even accepting that argument, the contention that Seaspray knew or should have known of the alleged practice of installing these above-ground pools in-ground is based solely upon the unsupported conclusory allegations of plaintiff’s expert. There is no submission that Seaspray knew that any of its pools were being installed in-ground, nor was there submission of any evidence demonstrating the existence of such knowledge generally within the pool industry (see, People v Jones, 73 NY2d 427; Matter of Riehl v Town of Amherst, 308 NY 212, 216; cf., Kriz v Schum, 75 NY2d 25; Denkensohn v Davenport, 75 NY2d 25). Under familiar rules "one opposing a motion for summary judgment must produce evidentiary proof in admissible form sufficient to require a trial of material questions of fact on which he rests his claim * * * mere conclusions, expressions of hope or unsubstantiated allegations or assertions are insufficient” (Zuckerman v City of New York, 49 NY2d 557, 562, supra). Inasmuch as we read plaintiff’s expert’s affidavit as containing only bare conclusory assertions in respect to industry-wide knowledge regarding in-ground installation of these above-ground pools, it was insufficient to raise a triable issue of fact, sufficient to defeat Seaspray’s motion for summary judgment.

Similarly, under the circumstances here presented, the allegations regarding the pool’s filtration system and the use of an aqua-colored vinyl lining in the pool fail to demonstrate a design defect sufficient to raise a triable issue of fact.

Accordingly, Seaspray’s motion for summary judgment was properly granted.

Ill

Turning next to the motions and cross motions of the Susis and Brothers, the submissions demonstrate, without contradiction, that the Susis had the pool installed, upon the advice of the distributor, Brothers, in a manner that concealed its true depth and gave it the appearance of being an in-ground pool. The Susis and Brothers argue, however, that Vincent’s act of diving into the pool which he knew to be shallow was the sole proximate cause of his injury and therefore his complaint must be dismissed as against them (see, Smith v Stark, 67 NY2d 693, supra; Boltax v Joy Day Camp, 67 NY2d 617; Howard v Poseidon Pools, 72 NY2d 972, supra). In the cited cases however, we were able to conclude as a matter of law, upon the uncontroverted facts established by the submissions of the parties that the conduct of the respective plaintiffs was the sole proximate cause of their injuries (Howard v Poseidon Pools, 72 NY2d 972, supra; Manning v Manning, 72 NY2d 972; Smith v Stark, 67 NY2d 693, supra) or was an unforeseeable superseding event, sufficient to break the causal chain and thus absolve the defendant of liability (see, Boltax v Joy Day Camp, 67 NY2d 617, supra; see also, Derdiarian v Felix Contr. Corp., 51 NY2d 308, 315; Prosser and Keeton, Torts § 44 [5th ed]).

By contrast, no such conclusion can be reached here. The Susis directed the in-ground installation of this above-ground pool upon the advice of Brothers and contrary to the explicit installation instructions of the manufacturer, Seaspray. Plaintiff contends that this installation contributed to the creation of the illusion that the pool was of a depth sufficient for diving; that although he was aware of shallowness around the edges of the pool, it appeared to be deep enough toward the center. Thus, he urges that it cannot be said as a matter of law, on this record, that " ' "only one [legal] conclusion may be drawn from the established facts” ’ ” (Kriz v Schum, 75 NY2d 25, 35, supra, citing Howard v Poseidon Pools, 72 NY2d 972, 974, supra; Derdiarian v Felix Contr. Corp., 51 NY2d 308, supra) or that his conduct in diving into this pool under the circumstances was "reckless conduct”, constituting an unforeseeable superseding event such as would absolve these defendants of liability (Boltax v Joy Day Camp, 67 NY2d 617, 620, supra). These factual issues raise questions for resolution by the jury and summary judgment was properly denied.

Accordingly, the order of the Appellate Division should be affirmed, with costs, and the certified question answered in the affirmative.

Titone, J.

(dissenting in part and concurring in part). The majority holds that the pool manufacturer in this case cannot be held liable, but the precise basis for its holding is unclear. At one point, the majority suggests that the pool’s in-ground installation constituted a "substantial alteration or modification” of the product by a third party, insulating the manufacturer from liability, even if the product change was known or foreseeable (see, Robinson v Reed-Prentice Div., 49 NY2d 471). In the very next paragraph, however, the majority appears to shift ground and, after identifying the problem as one of product misuse, seems to base its holding on the absence of proof that defendant Seaspray Sharkline, Inc. (Seaspray), the manufacturer, knew or should have known that in-ground installation of above-ground pools was a common practice. Neither rationale withstands close analysis. Accordingly, I dissent from the majority’s decision to dismiss the action against Seaspray.

Plaintiff Vincent Amatulli was seriously injured when he dove into a shallow backyard swimming pool owned by the Susis. The present suit, which included a claim against the pool’s manufacturer, was based on the theory that the aqua color of the pool liner, coupled with the fact that the pool had been sunken into the ground and encircled by a deck, created the illusion that the pool’s center was deep enough for diving. This theory was supported by an expert’s affidavit, which also faulted the pool manufacturer for not providing depth markings or adequate warnings against diving.

Initially, to the extent that the majority has rejected plaintiffs’ theory on the basis of the rule articulated in Robinson v Reed-Prentice Div. (supra), its reliance is misplaced. In Robinson, the purchaser of a plastic molding machine had deliberately removed a safety gate installed by the product’s manufacturer to protect operators from injury. Although there was proof that the manufacturer knew or had reason to know that the purchaser intended to modify the machine in this manner, the Court rejected an injured worker’s claims based on strict products liability and design defect theories, holding that "[substantial modifications of a product from its original condition by a third party which render a safe product defective are not the responsibility of the manufacturer” (49 NY2d, at 479). However, the Court also reaffirmed its commitment to the ’’[w]ell-settled” principle that "a manufacturer is under a duty to use reasonable care in designing [its] product when ’used in the manner for which the product was intended * * * as well as an unintended yet reasonably foreseeable use’ ” (id., at 480, quoting Micallef v Miehle Co., 39 NY2d 376, 385-386).

There thus exists a clear distinction between ’’substantial alteration” cases and cases involving unintended uses, or misuses, of a manufacturer’s product. Moreover, the distinction is one that should not be blurred or overlooked, since it determines whether an injured plaintiff may or may not recover upon proof of foreseeability.

Contrary to the view expressed by the Appellate Division majority (156 AD2d 500, 502), this is not a case of ’’substantial alteration or modification” of a product. Indeed, in this context, the ’’substantial alteration” rationale is nothing more than a red herring to be soundly rejected. First, and most obviously, plaintiffs’ claims here included a cause of action for failure to warn, as to which the Robinson holding is of questionable analytical utility (see, 1 Weinberger, New York Products Liability §23:10 [and authorities cited therein]). While the focus of a design-defect claim such as that asserted in Robinson is the product’s fitness for intended uses (see, 49 NY2d, at 479), the focus of a failure to warn claim such as that asserted here is whether there has been a breach of the manufacturer’s duty to warn consumers against using the product for unintended but foreseeable purposes (see, Kriz v Schum, 75 NY2d 25, 36; McLaughlin v Mine Safety Appliances Co., 11 NY2d 62; Lancaster Silo & Block Co. v Northern Propane Gas Co., 75 AD2d 55; see generally, 1 Weinberger, op. cit., § 18:13).

Furthermore, the Robinson holding was premised, in part, on the principle that the validity of a design-defect claim should be assessed by reference to the configuration of the product "as of the time [it] leaves the manufacturer’s hands” (49 NY2d, at 479, supra). In a failure-to-warn case such as this, the gist of the claim is that the product was, in fact, defective "as of the time [it] le[ft] the manufacturer’s hands” because of the failure to include warnings of known or knowable dangers, including the danger of in-ground installation. Thus, the Robinson Court’s concern about holding manufacturers responsible for the postsale handling of their products by others is not implicated.

Additionally, Robinson is inapplicable because, unlike the circumstances in that case, where the purchaser "destroy[ed] the functional utility” of a key safety feature by cutting a 6-by-14-inch hole in the plexiglass portion of the safety gate (49 NY2d, at 477, 480), no physical alteration was made in the configuration or structure of Seaspray’s swimming pool (see also, Sage v Fairchild-Swearingen Corp., 70 NY2d 579, 586 [stressing the physical alteration of the machinery in Robinson]). Rather, the Susis and the professional installers they hired simply failed to follow the manufacturer’s instructions for above-ground installation, placing the vinyl pool some two feet below ground level instead. At worst, this was an "unintended use” or a misuse of defendant Seaspray’s product analogous to the plaintiffs misuse of an aquatic slide as a diving platform in Denkensohn v Davenport (75 NY2d 25, 36). Indeed, if Robinson is applicable to this situation, it is difficult to imagine when, if ever, a manufacturer could be held liable for injuries occasioned by unintended, although foreseeable, uses of its products.

Particularly troubling is the majority’s strained effort to bring this case within the Robinson rule by likening the intended above-ground installation of this shallow pool to a form of "warning” analogous to the "safety feature” that was deliberately circumvented in Robinson (majority opn, at 533). First, despite the suggestion in the majority’s opinion (majority opn, at 533), there was nothing inherent in this four-foot pool’s "configuration” that made it an "above-ground” pool. To the contrary, as is apparent from this case, the pool’s "configuration” lent itself readily to in-ground uses. Thus, it was not the pool’s "configuration” that made it an "above-ground” pool; rather, it was made an "above-ground” pool by the accompanying installation instructions. The installer’s failure to follow those instructions certainly did not physically alter the product, much less alter it in such a way as to constitute a removal of a "safety feature”. Accordingly, there was no change in the pool’s "configuration” justifying the manufacturer’s failure to warn against foreseeable alternative installation methods, and the obligation to include appropriate warnings on that subject remains a question to be resolved by the fact finder.

Second, while it is true that this type of pool may be somewhat safer when its bottom rests on the ground and its shallowness is consequently apparent, the pool’s intended above-ground use can hardly be characterized as a "safety feature.” As plaintiffs expert noted in his affidavit, vinyl above-ground pools, which were first marketed to the American consumer about 30 years ago, were designed to eliminate the expense of excavating and laying down a concrete or tile liner, thereby making pool ownership available to a wide spectrum of consumers (see also, Broder, The Hazards of Swimming Pools, NYLJ, Mar. 4, 1991, at 3, 5). This "above-ground” feature had both a positive and a negative effect: on the one hand, it drastically reduced the cost of private backyard pools; on the other hand, it imposed severe limitations on the possible depth of such pools, thereby creating a greatly enhanced risk of injury to users (see, e.g., Kriz v Schum, supra; Howard v Poseidon Pools, 72 NY2d 972; Manning v Manning, 72 NY2d 972; Smith v Stark, 67 NY2d 693). The majority’s effort to transform this commercially useful feature into its own "warning” or "safety” device stretches that concept well beyond its ordinary bounds.

In truth, in-ground installation was not a change in the pool’s "configuration” or a conscious bypassing of a built-in safety feature (see, majority opn, at 532-533; Robinson v Reed-Prentice Div., supra, at 480), but rather was simply an unintended use of this four-foot vinyl pool. Accordingly, consistent with all of the prior unintended use cases including Denkensohn (supra, at 36), the extent to which this particular departure from the above-ground pool’s intended use constitutes a defense to plaintiffs’ claim should depend on whether it was foreseeable.

Despite its reliance on Robinson, the majority appears to acknowledge that liability could attach if Seaspray had been aware that these above-ground pools were being installed in the ground. Yet, the majority nonetheless finds reason to dismiss plaintiffs’ claim because, in its view, plaintiffs’ expert evidence on this point was both "unsupported” and "conclusory.” The expert, however, stated clearly and specifically that the practice of installing above-ground pools below ground level so as to convey the appearance of an in-ground pool "is well known in the pool industry” and "for many years * * * [has] been a common practice.” Such a statement, made by an expert with 30 years’ experience in the safety and construction of vinyl pools, would, if believed by a jury, surely have been sufficient to support a finding that Seaspray knew, or at least should have known, that its products might well be installed in the ground by end users, creating an enhanced risk of diving injuries. Indeed, this expert’s statement was no more, "conclusory” than the expert evidence in Denkensohn, which the Court accepted as being probative on the issue of whether the plaintiff’s misuse of the defendant manufacturer’s product was "predictable” (75 NY2d, at 36, supra [emphasis supplied]).

As to the majority’s alternative objection to the experts’ affidavit as "unsupported,” I know of no rule of law or prior precedent that considers expert evidence suspect or of such reduced quality that corroboration is, as a matter of law, required. To the contrary, in Nallan v Helmsley-Spear, Inc. (50 NY2d 507, 521) we accepted an expert’s statement on the deterrent effect of security guards as sufficient, in itself, to establish a prima facie claim of causation for submission to the jury (accord, Martin v Edwards Labs., 60 NY2d 417, 428-429 [accepting expert physician’s affidavit as sufficient to satisfy plaintiff’s obligation of going forward to defeat defense motion for dismissal]). The expert’s assertion here is entitled to be treated in the same manner, i.e., as sufficient, in itself, to raise a triable question of fact. The authorities on which the majority relies for the proposition that " 'facts or data’ ” are required to substantiate an expert’s statements (majority opn, at 534, n 2) are not helpful for the simple reason that the expert assertion at issue here — that an in-ground installation of these pools is an industry-wide practice — is a factual allegation and not a statement of conclusion or opinion.

In effect, by dismissing these plaintiffs’ expert evidence as "conclusory,” the majority has reached beyond its mandated "issue finding” function on these summary judgment motions and has instead improperly resolved a disputed factual issue on the basis of its view of the evidence’s weight. The result is that a potentially meritorious claim against a manufacturer that did not see fit either to provide adequate depth markers or to warn against the dangers of in-ground installation has been foreclosed. Since, in my view, plaintiffs’ claim against Seaspray is one that ought to be decided by a jury, I dissent from Court’s decision to dismiss it.

Chief Judge Wachtler and Judges Simons, Kaye and Bellacosa concur with Judge Alexander; Judge Titone dissents in part and votes to modify in a separate opinion in which Judge Hancock, Jr., concurs.

Order affirmed, etc. 
      
      . Summary judgment was granted to Delhi by Supreme Court and no appeal was taken, thus Delhi is not before us.
     
      
      . Although our dissenting-in-part colleague posits that the "expert’s assertion * * * is entitled to be treated * * * as sufficient, in itself, to raise a triable question of fact” (see, dissenting opn, at 540) the law is otherwise. "[W]here the expert states his conclusion unencumbered by any trace of facts or data, his testimony should be given no probative force whatsoever * ** * [i]ndeed, no reason is apparent why his testimony should not simply be stricken.” (See, McLaughlin, 1971 Practice Commentary, McKinney’s Cons Laws of NY, Book 7B, CPLR 4515, 1991 Supp Pamph, at 400, citing People v Samuels, 302 NY 163; see also, Sawyer v Dreis & Krump Mfg. Co., 67 NY2d 328, 335; Fallon v Hannay & Son, 153 AD2d 95, 101, 102; Mohan v Westchester County Med. Center, 145 AD2d 474.)
      Thus, unlike the bare submissions here, and contrary to the assertions of the dissent (see, dissenting opn, at 539) the opinion in Denkensohn v Davenport (75 NY2d 25) was deemed "probative” inasmuch as the submissions demonstrated that diving from the top of a pool-slide was "predictable” in light of the extensive industry-wide advertisements encouraging such diving and the issuance of regulations by the Consumer Products Safety Council requiring that warnings against careless misuse of these slides be affixed thereto.
     
      
      . I agree with part III of the majority’s analysis, which upholds plaintiffs’ claims against the other defendants.
     
      
      . In this regard, it is important to note that a warning against the risks of in-ground installation is not the equivalent of an antidiving warning.
     
      
      . In Robinson, the plexiglass section of the machine that was mutilated was obviously a part of a safety gate and, accordingly, there was no doubt that the "safety feature” designed by the manufacturer had been consciously bypassed. Here, in contrast, the intended above-ground use of the pool was not so clearly a "safety feature,” at least in the absence of a warning to that effect. Consequently, it cannot be said that this "safety feature,” to the extent it may be reasonably characterized as such, was deliberate or conscious, as Robinson apparently requires.
     