Ordered that the order is affirmed, with costs.
The key factors in determining whether leave to serve a late notice of claim should be granted are whether the claimant has demonstrated a reasonable excuse for failing to serve 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 ( Matter of Buddenhagen v Town of Brookhaven, 212 A.D.2d 605, 606; Matter of O'Mara v. Town of Cortlandt, 210 A.D.2d 337, 338; Levette v. Triborough Bridge Tunnel Auth., r 207 A.D.2d 330).
The petitioner did not offer an acceptable explanation as to why she did not serve her notice of claim sooner than 15 months after her claim arose, and failed to demonstrate that the County of Westchester acquired actual knowledge of the essential facts upon which her claim was based ( i.e., alleged gross negligence and willful misconduct by the Child Protective Services in intentionally failing to protect her infant daughter), within 90 days or a reasonable time thereafter. Additionally, the County of Westchester would be substantially prejudiced in defending itself on the merits because records in this case were expunged. Thus, the Supreme Court properly dismissed the proceeding.
O'Brien, J.P., Goldstein, McGinity and Luciano, JJ., concur.