Order, Supreme Court, Bronx County (Anita Florio, J.), entered February 27, 1992, granting petitioner’s motion for leave to deem the notice of claim as timely served, unanimously affirmed, without costs.
The trial court properly concluded that respondent New York City Housing Authority (NYCHA) acquired actual knowledge of the essential facts constituting the claim within the 90-day period for serving the notice of claim under General Municipal Law § 50-e (1) (a). The Housing Authority *368police report, filled out only two weeks after the alleged accident, indicates not only that NYCHA was given notice of the allegedly defective stairway, but that one of the Authority’s police officers investigated the site. Moreover, NYCHA received the notice of claim only one month after the expiration of the 90-day period, which is a "reasonable time thereafter” within the meaning of General Municipal Law § 50-e (5), and respondent failed to demonstrate any significant prejudice to its ability to investigate the claim arising from this one-month delay. Concur — Milonas, J. P., Wallach, Asch and Rubin, JJ.