Order unanimously affirmed with costs. Memorandum: Although defendant presented sufficient evidence to entitle it to summary judgment dismissing the complaint, plaintiff raised questions of fact concerning causation, notice and the existence of a dangerous condition on the stair in defendant's school where plaintiff's son fell, thereby warranting denial of defendant's motion (see generally, Zuckerman v. City of New York, 49 N.Y.2d 557, 562).
Although slight differences in elevation have been held to be nonactionable (see, Morales v. Riverbay Corp., 226 A.D.2d 271; see also, Julian v. Sementelli, 234 A.D.2d 866; Guerrieri v. Summa, 193 A.D.2d 647), the same cases also hold that even a trivial height differential may be actionable where the defect constitutes a trap, snare, or nuisance. Plaintiff submitted an affidavit of a licensed engineer whose opinion it was that the repair in the stair constituted a trap, notwithstanding its minimal height differential, because the depression in the front part of the repair was not readily observable under normal conditions, thus creating a question of fact whether the defect constituted a dangerous condition.
The remaining contentions of defendant lack merit or are not preserved for our review (see, Walker v. Huber, 254 A.D.2d 734; Matter of Rodgers v. Crumb, 242 A.D.2d 874).
Present — Green, J. P., Pine, Wisner, Balio and Boehm, JJ.