The fire started at 17 East 184 about 6:20 a.m., but quickly spread to two adjacent buildings, fire officials said.
FDNY Deputy Chief Ron Werner said when firefighters tried to enter the two-story structure, it became engulfed with flames.
"The firefighters had to move in and try to put the fire out on the lower floors and continue to move up. But in doing that, the upper floors became completely controlled by fire," Werner said. "They did a valiant effort to try to save the building, but unfortunately, because of the amount of fire, we had to back them out."
Anna Caridad, 28, who lives nearby, said the flames shot out of the building.
"The flames were big," she said. "There was red and orange everywhere. I've never been that scared in my life."
Seven firefighters suffered minor injuries and were taken to nearby hospitals, Werner said. Another person was treated at the scene for minor injuries, he added.
The fire was brought under control a little more than an hour later, Werner said.
The American Red Cross of Greater New York was on scene and provided assistance to 26 people affected by the fire.
"Some of them are shaken up," said Cathy Hartwell, a Red Cross spokeswoman. "They're safe, and that's what they can be happy about."