An official said that some residents who live on upper floors of the building had not been able to get out as of noon, but that no one was dangerously trapped.
A call came in for the fire at 500 West 43rd Street, which is on 10th Avenue, at 11 a.m., according to the FDNY.
It is unclear what sparked the fire.
An FDNY official said two people were injured and taken to nearby hospitals in critical condition.