Three floors of John F. Kennedy High School in the Bronx were devastated and three workers injured — one critically — in a powerful explosion Thursday night.
Contractors were building science labs on the sixth floor, officials said, when the walls blew out.
Whether the Kennedy campus, home to eight schools and 4,000 students, will be able to open on the first day of school Sept. 9, is uncertain now, officials said.
“A very troubling evening for residents in Marble Hill. They felt a blast, they felt the building shake and what we see here at JFK High is a shocking scene,” Mayor de Blasio said at a news conference at the scene in Marble Hill.
While structurally okay, the building suffered major damage on three floors, said FDNY Commissioner Daniel Nigro.
The Times quoted police sources who said workers "were draining gas from a main in the lab ... but failed to drain it completely, setting off the blast" as they began work.
Con Edison is investigating.
The blast happened around 8 p.m. The school is located in Marble Hill, which is physically in the Bronx, but falls under the jurisdiction of Manhattan.
The victims were taken to Jacobi hospital. One man with severe burns to his body is in critical condition, and two others who suffered hand and body burns are in stable condition.
Custodians described the frightening moment the building went boom.
"We were just getting ready to go back to work and everything. We would never have expected that to happen," Addae Hicks told NBC4. "I thought it was a bomb, the way we felt it, it was just crazy."
Nearby neighbor Larissa Alvarado said her E. 228th street house "shook completely."
"I thought the whole house was going to fall down. It was really, really scary."