Friends tell police that the teen took magic mushrooms.
But, they're not sure how much of the hallucinogen he consumed.
Police are trying to figure out if the fall was an accident or a suicide.
Friends laid out flowers and taped up notes remembering 19-year-old Michael Simmons.
They say he was talented actor with a bright future.
The Arizona native was studying at the New York Conservatory of Dramatic Arts.
"We're trying to hold up. Everyone is trying to get through this," said Chris Vedutis, a student.
It happened Sunday around 2 a.m. at Simmons' dorm on Henry Street in Downtown Brooklyn.
Gokhan Yacizi says Simmons' body hit the pavement inches away from his food cart.
He says students watched in horror as his body fell from an eighth floor window.
"The students that were waiting here were screaming. It was a mess. It was awful," Yacizi said.
There are grief counselors for students both at the student's school and at his dorm.
Police are trying to figure out if he jumped or slipped.
David Palmer, The New York Conservatory of Dramatic Arts' Chief Executive released a statement saying: "We are deeply saddened by this tragedy".