The 36-year-old man, whose name has not been released, was in a locked bathroom of Public School X811, a special education school on Longfellow Ave. near Jennings St., just before 6:10 p.m., sources said.

The teacher may have been dead for a few hours, since he was last seen at the end of the school day, sources said.

A staff member found him after forcing open the bathroom door, sources said. Police found drug paraphernalia near the teacher, including a glassine envelope with an unknown substance inside, sources said.

“This is deeply saddening and my heart goes out to the teacher’s family and the school community,” city schools Chancellor Carmen Fariña said.

“We will be providing grief counselors and ongoing resources to support students and staff during this difficult time.”

The city medical examiner’s office will determine his exact cause of death.