The fire, which tore through a first floor restaurant on East 53rd Street around 6 a.m., forced part of First Avenue to be shut down. Firefighters had hoses stretched across the roadway.
The 5-story building between First and Second avenues was evacuated.
No injuries were reported.
The blaze originated in the basement and spread to the first and second floors. Smoke could be seen for miles.
More than 100 firefighters fought the blaze.