The fire broke out on the first floor of a five-story apartment building on First Avenue just after 1:45 a.m.
Photos from the scene of the fire
Officials said the fire presented a challenge after the flames spread to a small section of rear of the building, which partially collapsed and could not be accessed safely by firefighters.
"Much of the roof on the first floor extension has burned away, but because of the collapse hazard, we can't get in there," FDNY Chief of Department James Leonard said. "And that's the problem, why we can't put this fire out right now."
Meantime, heavy smoke from that smoldering part of the building prompted firefighters to evacuate five adjacent buildings.
Fourteen firefighters were treated for minor injuries, mostly smoke inhalation, while other firefighters were also treated for heat exhaustion. Three residents suffered injuries described as minor.
As the smoke spread, firefighters also recommended the Department of Education close two nearby schools so students would not be exposed to the smoke.
Those school include East Side Community High School at 420 East 12th Street near First Avenue and P.S. 19 at 185 First Avenue near East 12th Street.
As a result, students were redirected to nearby schools, according to City Councilperson Carlina Rivera. The schools planned to reopen for Thursday.
EAST VILLAGE FIRE UPDATE: 1st Avenue fire started early this morning w/some injuries reported & nearby buildings impacted. Three local @NYCSchools’ students redirected to neighboring schools. https://t.co/Z8u9sSAiPR— Carlina Rivera 利華娜 (@CarlinaRivera) October 3, 2018
Three of the buildings that were evacuated will remain empty until the buildings department checks the structural integrity. The Red Cross is housing 13 residents.
The cause of the fire is under investigation.
WATCH raw video from NewsCopter7 and Eyewitness News on the ground
* More Manhattan news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube