Firefighters arrived at the fire at 660 East 187th St. in the Belmont section in less than four minutes, but it was already well-advanced because officials say the door to the fire apartment was left open, the front door of the building was propped open and the exit door to the roof was also open.
They say that created a "flow path," or wind tunnel of fire blowing through the apartment building.
The fire ultimately killed two people, two women, and injured nearly a dozen others, including five firefighters.
FDNY officials say victims did not have to die.
"If not for the doors being open, we believe that the fire may have even been contained to that one apartment, and we would have not lost anybody in that fire," FDNY First Deputy Commissioner Daniel Flynn said.
The two women were both found in the stairwells, attempting to descend from the upper floors, but the fire was blowing up the stairwell and coming at them.
"The interior stairs were compromised due to the door of the fire apartment left open," Flynn said. "They were caught in their tracks. They didn't have a chance."
Officials say they could have used the fire escapes to get out. Others were saved and rescued by firefighters using the fire escape.
"People were trapped in that building. People were hanging out of windows," Flynn said, calling the numerous rescues heroic.
Fire officials said while two people died and a third was critically injured, the actions of firefighters saved countless lives.
Fire marshals are working to determine what caused the deadly blaze.
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