Grief counselors are on hand at a Bronx school after a teacher was found dead of an apparent overdose Thursday evening.

Police say the 36-year-old male teacher was found inside a bathroom at Public School X-811 in Foxhurst around 6 p.m.

Sources say police also found a needle and a small bag with an unknown substance inside of it.

Parents and staff NY1 spoke to said the death is a huge loss for the school.

"It just hurts to know. It sent chills throughout my whole body, and I just couldn't believe it because he was a young guy, he was a great guy from what I know. I used to say hi to him in the morning, I didn't know him personally, but you ask anybody in the school it's nothing but good things," said one person at the scene.

"He was a very good teacher and I really cared for him. He was really good, really nice with the kids. It's heartbreaking what happened to him," said another person at the scene. "It is a big loss because he was somebody who was always hands on with the kids. He always gave them a positive vibe at all times."

It's now up to the city's medical examiner to determine the exact cause of death.

The investigation is ongoing.