The city is trying to figure out how a boy with autism was able to walk out of his Brooklyn school unnoticed.
The mother of 6-year-old Abraham Awawda says he left P 77-K in Borough Park on Friday.
The special needs school is housed in the same building as P.S. 164.
She says school staff did not realize her son - who's non-verbal - was missing until his bus driver asked for him.
He was gone for more than an hour and was later found inside an apartment building three blocks away.
Schools Chancellor Carmen Fariña says officials are working to get answers.
"Well first of all, safety is always our first concern," Chancellor Fariña said. "All protocol in this particular case was followed and the child was found and we're working with the school at this time."
The boy's mother says a retired cop found him looking over the edge of a balcony in the building.