The plaintiff, who was then 85 years of age, allegedly slipped and fell at the defendants’ restaurant while walking down a staircase consisting of three steps. The defendants established their prima facie entitlement to judgment as a matter of law by submitting the plaintiff’s deposition testimony, in which she was unable to identify the cause of her accident without engaging in speculation (see Dalinedesroches v Lazard, 70 AD3d 626 [2010] ; Bolde v Borgata Hotel Casino & Spa, 70 AD3d 617 [2010]; Morgan v Windham Realty, LLC, 68 AD3d 828, 829 [2009]; Reiff v Beechwood Browns Rd. Bldg. Corp., 54 AD3d 1015 [2008]; Teplitskaya v 3096 Owners Corp., 289 AD2d 477, 478 [2001]). The defendants also established that they did not create a dangerous or defective condition, and did not have actual or constructive notice of the existence of any such condition for a sufficient length of time to discover and remedy it, as required in an action alleging premises liability (see Gordon v American Museum of Natural History, 67 NY2d 836, 837 [1986]; Shindler v Warf, 66 AD3d 762, 763 [2009]; Crawford v AMF Bowling Ctrs., Inc., 18 AD3d 798, 799 [2005]; Gloria v MGM Emerald Enters., 298 AD2d 355 [2002]).
The admissible evidence which the plaintiff submitted in opposition to the defendants’ motion failed to raise a triable issue *1005of fact as to the cause of the accident (see Dalinedesroches v Lazard, 70 AD3d at 626; Morgan v Windham Realty, LLC, 68 AD3d at 829; Teplitskaya v 3096 Owners Corp., 289 AD2d at 478). The affidavit of a nonparty witness relating to the defendants’ notice of the alleged dangerous condition could not be considered in determining the motion, as the witness was not properly disclosed as a notice witness (see Muniz v New York City Hous. Auth., 38 AD3d 628 [2007]; Williams v ATA Hous. Corp., 19 AD3d 406, 407 [2005]).
Accordingly, the Supreme Court should have granted the defendants’ motion for summary judgment dismissing the complaint. Angiolillo, J.E, Balkin, Chambers and Cohen, JJ., concur.