The Red Cross said the fire displaced 45 people, including seven children, from 18 households and 27 apartments in the building. The city's Department of Buildings will determine whether the structure is safe before residents are allowed to return home.
One person was killed and 14 others were injured in the blaze, according to officials.
The fire was first reported on the building's second floor shortly after noon Wednesday. It reached five alarms just before 2 p.m. and was brought under control shortly after 8 p.m.
Residents told Eyewitness News they smelled gas before an explosion rocked the building, sending flames racing through the structure.
Officials said there were collapses on the building's second and third floors. Search and rescue teams later found a man, believed to be in his 40s, dead on the collapsed third floor.
Eight civilians were injured, including two with life-threatening injuries, two with serious injuries and four with minor injuries. Six firefighters were also hurt, including three with serious injuries and three with minor injuries.
Among those critically injured was a 48-year-old woman who lived in the second-floor apartment where the fire is believed to have started. Officials also said one of those injured was a child younger than 1 year old, whose injuries were believed to be minor.
"The firefighters were rescuing people from the building and EMS was providing lifesaving treatment right on the scene, saving multiple lives," FDNY Commissioner Lillian Bonsignore said.
Residents described the frightening moments after the explosion.
"We all heard a boom. I thought the building collapsed. It felt like an earthquake," one resident said.
Another neighbor said the blast caused the ceiling to collapse inside their apartment.
"I heard an explosion and then the ceiling fell and hit me in my head," the resident said.
A resident who entered the apartment where the fire started said flames spread rapidly from the kitchen.
"The fire was from the kitchen. The stove, there was fire... the whole closet was in flames," the resident said.
More than 300 firefighters responded to the scene. Officials said the explosion blew hinges off doors and window frames across the street, creating dangerous conditions for firefighters as they searched the building.
The city's Department of Buildings must determine whether the structure is safe before residents are allowed to return home.
FDNY officials said they reviewed department call logs and found no reports of gas leaks at the building this year. Con Edison shut off gas service to the building after the explosion.
The cause of the explosion and fire remains under investigation.
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