Here, the petitioners failed to demonstrate that the City obtained timely, actual knowledge of the essential facts constituting the claim (seeParker v. City of New York, 206 A.D.3d 936, 937, 170 N.Y.S.3d 603 ; Matter of Wieman–Gibson v. County of Suffolk, 206 A.D.3d 666, 667, 170 N.Y.S.3d 123 ; Joseph v. New York City Tr. Auth., 237 A.D.2d 255, 256, 655 N.Y.S.2d 396 ). In order for a municipality to have actual knowledge of the essential facts constituting the claim, "[it] must have knowledge of the facts that underlie the legal theory or theories on which liability is predicated in the notice of claim" ( Matter of Felice v. Eastport/South Manor Cent. School Dist., 50 A.D.3d 138, 148, 851 N.Y.S.2d 218 ; seeMatter of Ramos v. Board of Educ. of the City of N.Y., 148 A.D.3d 909, 911, 49 N.Y.S.3d 539 ). Unsubstantiated and conclusory assertions that the municipality acquired timely actual knowledge of the essential facts constituting the claim through the contents of reports and other documentation are insufficient (seeParker v. City of New York, 206 A.D.3d at 938, 170 N.Y.S.3d 603 ; Humsted v. New York City Health & Hosps. Corp., 142 A.D.3d 1139, 1140, 37 N.Y.S.3d 899 ; Matter of Padgett v. City of New York, 78 A.D.3d 949, 950, 912 N.Y.S.2d 75 ).

However, plaintiff may move for leave of the court to file a late notice of claim if he demonstrates a reasonable excuse for the failure to file a timely notice of claim, whether the municipality acquired actual knowledge of the essential facts constituting the claim within 90 days of its accrual or a reasonable time thereafter, and whether the delay would substantially prejudice the municipality in maintaining its defense on the merits. (Joseph v. New York City Transit Authority, 237 AD2d 255 [2nd Dept. 1997].) Defendants demonstrated a prima facie entitlement to summary judgment.