A major fire in a residential apartment building in the Bronx in New York City sent 32 people to hospitals with life-threatening conditions, FDNY Commissioner Daniel Nigro said Sunday.

About 200 members of the New York City Fire Department were on scene of the fire at a 19-story apartment building at 333 East 181st Street. The fire began a little before 11 a.m. and has been “knocked down,” the FDNY said.

The fire started in a duplex apartment on the 2nd and 3rd floors of the building, Nigro said. The door to the apartment was left open, and smoke then spread to every floor of the building, he said.

Firefighters were met by “very heavy smoke, very heavy fire” in the hallways.

Victims were found in stairways on every floor of the building, many in cardiac arrest, in what Nigro said could be an unprecedented loss of life. The injuries were predominantly from smoke inhalation, he said. The FDNY told media 54 people were injured.

The FDNY posted several images of the scene at 333 East 181st Street showing ladders extending into apartment windows as well as a number of broken windows.