In affirming the denial of the petition to file a late notice of claim against a public corporation, the Second Department explained the doctrine of equitable estoppel as it applies to public corporations:

Estoppel against a public corporation will lie only when the public corporation’s conduct was calculated to, or negligently did, mislead or discourage a party from serving a timely notice of claim and when that conduct was justifiably relied upon by that party … . Here, the petitioner failed to demonstrate that the respondents engaged in any misleading conduct that would support a finding of equitable estoppel … . In addition, there was no evidence that the respondents made any settlement representations upon which the petitioner justifiably relied prior to the expiration of the statutory periods for serving a notice of claim or seeking leave to serve a late notice of claim and, therefore, the petitioner could not have relied on any conduct by the respondents in discouraging him from serving a notice of claim or seeking leave … .  Attallah v Nassau Univ. Med. Ctr., 2015 NY Slip Op 06587, 2nd Dept 8-19-15