At least 3 dead, 14 injured in large fire at Brooklyn residential building

BROOKLYN, New York -- A fast-moving fire in a residential building in New York City left at least 14 people injured and three dead.

Firefighters were called to the scene in Crown Heights, Brooklyn around 4:30 a.m. Sunday.

The flames began on the ground floor and quickly engulfed the three-story building.

Very intense smoke and flames made the work of firefighters very difficult.

FDNY Chief John Esposito described the rescue efforts as a "very dangerous operation."

"A fire operation like this, when you have heavy fire on multiple floors of the building, it's time consuming to extinguish," he said. "We had to stretch multiple hand lines to each floor. Very dangerous operation for all firefighters."

Three people needed immediate CPR and were transported to hospitals in critical condition.

According to the FDNY, those victims were later pronounced dead at the hospital.

Most of the other patients at the scene were assessed for smoke inhalation and released.

One firefighter suffered a serious but non-life-threatening injury.

It's unclear what caused the fire or whether smoke detectors were inside and operational at the time.