In a tragic story from a different part of the globe, a 6 year-old boy was blinded in one eye when a fellow student hurled some mud his way. Unfortunately for this 6 year-old, this particular clump of mud also contained a nail, which pierced his eye.
Although the mother of this boy is charging her son's school with negligence for failing to clear the yard from nails, it is highly unlikely that a negligence claim against a school district or daycare such as this would survive under New York law.
The mother would have to show that the school either knew of the particular dangerous condition, or should have, in the exercise of proper caution, known about it, yet failed to remedy the problem in a timely and appropriate way.
I doubt she will be able to marshall such proof.
For additional information on this topic, I recommend that you read "How to Prove Your School Negligence Case Under New York Law."