Order unanimously affirmed without costs. Memorandum: Supreme Court properly denied plaintiff’s motion for partial summary judgment on his Labor Law § 240 (1) cause of action. Plaintiff alleges that, while performing repair work on defendant’s power house building, he was injured when the ladder he was climbing tipped to one side and both he and the ladder fell to the ground. The accident was not witnessed. To recover under section 240 (1) of the Labor Law, plaintiff must demonstrate that he was injured in a fall from an elevated worksite or that he was struck by an object that fell from an elevated worksite (see, Staples v Town of Amherst, 146 AD2d 292). Whether plaintiff fell while on the ladder or was injured in some other manner is, therefore, a critical factual issue. Because the manner in which the accident occurred is within the exclusive knowledge of the plaintiff, partial summary judgment is not appropriate (see, Parsolano v County of Nassau, 93 AD2d 815; Bruno v Home Mut. Ins. Co., 91 AD2d 1169). Plaintiff’s testimonial version should be subjected to cross-examination and his credibility assessed by the fact finder after a trial (see, Castillo v General Acc. Ins. Co., 111 AD2d 112, 113; Krupp v Aetna Life & Cas. Co., 103 AD2d 252, 262; Siegel, Practice Commentaries, McKinney’s Cons Laws of NY, Book 7B, CPLR C3212:19). (Appeal from order of Supreme Court, Monroe County, Curran, J.— summary judgment.) Present—Dillon, P. J., Callahan, Green, Balio and Lowery, JJ.