UPDATE: The New York Post reports that the man, Mohammad Saram, has died.
EARLIER: A Brooklyn man is in critical condition after accidentally setting fire to himself while working with chemicals, according to fire officials.
Surveillance video obtained by the Daily News shows the man running through the street in flames and then smoldering on the sidewalk.
"I was yelling 'drop, drop, roll!'" witness Alex Mayer told NY1. "He was completely engulfed in flames. He was really burning. It was very scary. It actually looked like a stunt or something."
Mayer and another witness, a truck driver identified only as Claude, brought the burning man to the ground.
"He dropped on his side to roll, but he was still on fire," Claude told ABC New York. "And I took the fire extinguisher out of the truck and I sprayed him... It put the fire out."
Other witnesses told ABC that the man's clothing burned right off his body. Footage from the scene, below, shows scraps of burned clothing and shoes in the street.
PIX 11 reports that the man has second- and third-degree burns over 80 percent of his body.
“He was really badly burned,” an FDNY source told the Daily News.
It's not clear how the fire started, but the Daily News reports that the man was planning to open a hookah shop and was working with chemicals, possibly acetone and coconut oil, to dry the tobacco when something ignited. The newspaper says there was a small explosion before he came running out of a building.
“The fire department units extinguished the fire and right now at this time we have hazmat units are testing some unknown chemicals found in the basement,” Acting Deputy Chief Division 8 Battalion Mark Egan told the New York Post.