The incident was reported at a building on East 42nd and Second Avenue -- 235 East 42nd Street -- around 8 a.m. E.T.
Officers say the workers spotted structural support beams beginning to buckle on the 21st and 22nd floors, and self-evacuated, according to the New York Police Department.
Officials say that caused the 21st to 26th floors of the building to start caving under the stress.
The New York City Fire Department said the following buildings have been evacuated:
- 815 Second Avenue
- 235 East 42nd Street
- 210 East 43rd Street
- 212 East 43rd Street
- 211 East 43rd Street
- 231 East 43rd Street
- 225 East 43rd Street
- 235 East 43rd Street
Of the evacuated buildings, 231 East 43rd Street is the Hampton Inn Manhattan Grand Central, and guests have been evacuated out of their rooms.
Pedestrian and vehicular traffic is closed on East 42nd Street between Second and Third avenues.
The FDNY has also asked for East 44th Street to be closed between Second and Third avenues.
The 38-story building under construction is the former Pfizer headquarters and is currently being converted from offices to apartments. It is currently the largest office to apartment conversion in city history.
When completed, the building will house 1,600 apartments, including over 400 affordable housing units.
No injuries have been reported and all workers are accounted for.
DOB inspectors and engineers are on site working quickly to secure the site, as well as that surrounding area, according to officials.
The investigation remains ongoing.