Doctors are working to save the lives of those injured in a New York City apartment fire that killed 17 people, including eight children, over the weekend, the Associated Press reports.

The five-alarm fire began just before 11 a.m. on Sunday with a space heater malfunctioning inside a bedroom, causing smoke to rapidly spread through the 19-story building and stopping some people from escaping and incapacitating others who tried. FDNY Commissioner Daniel Nigro said the smoke spread because of an open door.

"The smoke spread throughout the building, thus, the tremendous loss of life and other people fighting for their lives right now in hospitals all over the Bronx," Nigro said.

Of the 63 people injured in the blaze, CNN reports that 32 suffered life-threatening injuries. Victims were found on every floor in the stairways with many suffering from cardiac and respiratory arrest.

“We pray to God that they’ll be able to pull through,” said New York City Mayor Eric Adams. Adams said firefighters worked to save lives after their oxygen tanks ran out.

It was commonplace for fire alarms to go off inside the building, according to residents, so many ignored the warnings, the AP reports. The building is not equipped with fire escapes.

The fire was New York City’s deadliest since 1990 when 87 people died in an act of arson at the Happy Land Social Club in the Bronx. The Bronx is also home to a 2017 fire that killed 13, and a 2007 space heater fire that killed nine.