On the morning of December 18, 1945, Hugh Scott, an elevator operator, had been helping a mechanic repair an elevator in their employer’s building. The work completed, except for the installation of a bolt, the mechanic went for a special type of wrench to fasten the bolt, leaving Scott standing in the corridor near the elevator with nothing to do. A few minutes later, Scott was found on the corridor floor, unconscious and on his back, with froth coming from his mouth. The elevator had not been moved and the bolt had not been touched. No one had seen Scott fall, and, when he regained consciousness, he said that he did not know what had happened. He died some two weeks later, the autopsy revealed, from a cerebral hemorrhage caused by the rupture of a pre-existing aneurysm, situated at the base of the brain. The autopsy report also indicated that there were no scars on Scott’s face, no marks on his body and no fracture of his skull.
An award to Scott’s dependents was made by the Workmen’s Compensation Board, and affirmed by the Appellate Division, on the ground that the employee had been the victim of an industrial accident and that his fall had not been occasioned by “ any underlying pathological condition ”.
While a reviewing court may not substitute its own judgment on the evidence for that of an administrative tribunal, it will not. of course, accept or confirm a determination merely *9because made by such an agency. Our study of the present record demonstrates that the finding that there was an accident, far from being supported by substantial evidence, rests wholly upon conjecture. There is no evidence that Scott was working in or about the elevator when he fell, that he struck his head before he fell or suffered any trauma, or that the fall was caused by any exertion or strain — usual or unusual —• or by any condition of his employment. Absent such proof, the only reasonable conclusion possible is that the aneurysm ruptured spontaneously and that it was that that rendered him unconscious and caused him to fall to the floor.
The sole item in the record that might conceivably be claimed to support the finding of accident is the testimony of a physician, Dr. David Shapiro — who had made a “ casual ” examination of Scott immediately after his collapse — that he noticed a slight skin abrasion on Scott’s forehead and that, while there was no doubt that the aneurysm could have ruptured spontaneously, there was a possibility that the rupture might have been caused by a blow, if indeed there had been a blow. There is, as already noted, no proof of any blow, and Dr. Shapiro himself acknowledged that he had " no way of determining ’ ’ what had caused the abrasion or even when it had been sustained. Quite obviously, the statement of such a possibility, founded as it was upon a hypothesis having no support in the record, is a far cry from proof of any fact, and may not, even when considered alone, be deemed to satisfy the requirements of the substantial evidence rule. And, when viewed in the light of the record as a whole — as, of course, it must be (see Matter of Stork Restaurant, Inc., v. Boland, 282 N. Y. 256, 275; see, also, Universal Camera Corp. v. National Labor Relations Bd., 340 U. S. 474, 487 et seq.; Benjamin, Judicial Review of Administrative Adjudication, 48 Col. L. Rev. 1, 2-3) — there can be no doubt whatsoever that the doctor’s surmise of what might have been, may not be regarded as substantial, for opposed to it is not only proof that Scott collapsed while waiting, with nothing to do, for his fellow-employee to return; not only proof that he died of a ruptured aneurysm of long standing; but also positive and unequivocal testimony of two other physicians, experienced neurologists, that the rupture was spontaneous and could not *10have been caused by any trauma. (See, e.g., Matter of Kristiansen v. Frank McWilliams, Inc., 300 N. Y. 728; Matter of Fish v. Wickwire Spencer Steel Co., 258 N. Y. 539; Matter of Hansen v. Turner Constr. Co., 224 N. Y. 331; Matter of Williams v. Pittsburgh Plate Glass Co., 268 App. Div. 334.)
Cases such as Matter of Green v. Geiger (253 App. Div. 469, 255 App. Div. 903, affd. 280 N. Y. 610), relied upon to support the award, are not in point. In the Geiger case, there was present — what is here lacking — significant proof that, immediately before the employee collapsed of a coronary thrombosis, he had been subject to work involving unusual exertion and physical strain which had put a heavy burden on his already weakened heart. On the other hand, persuasive precedent is furnished by such cases as Matter of Kristiansen v. Frank McWilliams, Inc. (supra, 300 N. Y. 728), Matter of Fish v. Wickwire Spencer Steel Co. (supra, 258 N. Y. 539), and Matter of Hansen v. Turner Constr. Co. (supra, 224 N. Y. 331), in each of which we reversed an award in favor of the claimant because there was no evidence of an industrial accident. In the Fish case (supra, 258 N. Y. 539), for example, an employee, who had been at work in a factory, was discovered lying unconscious on a cement platform with a cut over one eye. No one had witnessed an accident and no one had seen him fall. It was later ascertained — just as in this case — that death was owing to the rupture of an aneurysm, and — again, just as in the present case — a doctor testified that a blow could have produced the rupture. This court reversed the board’s determination “ on the ground that the evidence does not show that the death was due to an accident arising out of the employment ” (p. 540). So, here, while Scott’s collapse occurred “ in the course of ’ ’ his employment, there is no evidence to indicate that his death stemmed from any accident, much less from an accident “ arising out of ” such employment.
Nor may the determination be rested upon the presumption created by section 21 of the Workmen’s Compensation Law. Compensation awards have, it is true, been upheld times without number on the strength of that presumption in cases where, there have been obvious signs of violent injury, causing disability. to furnish basis for a finding that the accident, which *11no one had witnessed or observed, arose “ out of and in the course of ” employment. (See, e.g., Matter of Kleid v. Carr Bros., 300 N. Y. 270; Matter of Welz v. Markel Service, Inc., 296 N. Y. 640; Matter of Gallagher v. Mundett Cork Co., 295 N. Y. 576.) The presumption, however, is a limited one, operating, the statute specifies, only “in the absence of substantial evidence to the contrary ”. Moreover, as this court has frequently ruled, “it cannot be used as a substitute for actual proof ”. (Matter of Wilson v. General Motors Corp., 298 N. Y. 468, 472; see, also, Matter of Dyviniek v. Buffalo Courier Express Co., 296 N. Y. 361, 364.) Consequently, where as in the present case, there is no evidence at all of industrial accident or of accidental injury, the lack of such evidence may not be supplied by the presumption; in other words, section 21 may not be availed of, or the presumption utilized, to establish the incident of accident itself. (See, e.g., Matter of Kristiansen v. Frank McWilliams, Inc., supra, 300 N. Y. 728; see, also, Matter of Dyviniek v. Buffalo Courier Express Co., supra, 296 N. Y. 361, 364; Matter of Daus v. Gunderman & Sons, Inc., 283 N. Y. 459, 466; Matter of Lorchitsky v. Gotham Folding Box Co., 230 N. Y. 8, 12; see, also, Matter of Pinto v. Chelsea Fibre Mills, 196 App. Div. 221, 223.) In any event, even if it were held that the presumption had some proper place in this case, it could not survive the unquestionably “ substantial evidence to the contrary ”— evidence that Scott’s collapse and death resulted from a spontaneous rupture of a pre-existing aneurysm and could not have been caused by any blow or other trauma.
The order of the Appellate Division and the award of he Workmen’s Compensation Board should be reversed, with costs in this court and in the Appellate Division, and the claim for compensation dismissed.