As noted previously, the most critical mistake to avoid when suing a New York municipality is failing to file in a timely fashion the Notice of Claim, which must, as a general rule, be done withing 90 days of the incident or occurrence.
But there is a second, equally - if not more - important rule when suing for school negligence or negligent supervision against a New York municipality, and that is identifying the specific entities that need to be sued.
For example, in New York City, under NYC Charter §521(a), while the property on which the public schools sit is owned by New York City, those premises remain under the Department of Education ("DOE")'s control and care "for purposes of public education, recreation, and other public uses." Thus, if you only sue New York City for school negligence or negligent supervision, there is a chance that a Court will dismiss your case. (While there are some courts, like in Kamara v. The City of New York, holding that suit against New York City alone - rather than separately naming the Department of Education - is acceptable, there are also some cases that have held differently on the subject.
One thing is clear: you really don't want to run that risk.