The deadly Bronx apartment fire was caused by a faulty space heater, fire commissioner says

• On Sunday, 19 people, including nine children, were killed in an apartment fire in the Bronx.
• The FDNY commissioner said a space heater started the fire, and smoke spread to the entire building.

The fire that killed 19 people in the Bronx borough of New York City on Sunday was started by a faulty space heater, the New York City fire commissioner said.

"The marshals have determined through physical evidence, through firsthand accounts from the residents, that this fire started in a bedroom in a portable electric heater," Daniel Nigro said at a press conference on Sunday, NBC News reported.

The heater had been "malfunctioning," he said, USA Today and The New York Times reported.

An unnamed city official told The Times that fire officials believed the space heater had been running uninterrupted for days in an attempt to add more heat to the building, even though the building's heat was turned on at the time.

Nigro said smoke spread through the entire building, likely with the help of open doors, NBC News reported.

At least 19 people, including nine children, were killed as a result of the blaze, and at least 13 others were hospitalized with life-threatening injuries, Reuters reported, citing officials.

Nigro said people affected by the fire were found on every floor of the building, as well as in stairways, NBC reported.

"Smoke spread throughout the building, thus the tremendous loss of life and other people fighting for their lives," he said, The Times reported.