Someone called 911 to report an odor of gas just before 2 p.m.
Firefighters responded and discovered high carbon monoxide readings.
Officials said between 40 and 50 people were evacuated from buildings on Stratford Rd. in Prospect Park South.
MTA buses were called in to shelter the people who were evacuated.
No injuries were reported.
The Office of Emergency Management said the National Grid was on scene inspecting their infrastructure.
Elsewhere in the city, trucks were out salting side roads near the George Washington Bridge and other locations, and driving conditions were generally wet.
But the winter weather continued to cause trouble.
Video from the Citizen app shows flames shooting from a manhole at West 164th Street and Edgecomb Avenue in Washington Heights.
New York City
The New York City Department of Sanitation issued a Snow Alert for Thursday, which means Roadway Dining and Open Streets are suspended. Sidewalk dining can still continue.
Alternate Side Parking has also been suspended through Saturday, though meters will be in effect.
Officials warned the Thursday evening commute could be difficult, with the heaviest snow expected to fall between 11 a.m. and 5 p.m. If you don t have to drive, please stay off the roads, NYC Emergency Management Commissioner Deanne Criswell said.
Diana Rocco has the latest on road conditions as another winter storm hits New York City.