The 5-story brownstone on West 123rd Street collapsed shortly before 5:00 p.m.
Fire officials say the building was under renovation.
They don't believe anyone was inside at the time, but they searched the rubble as a precaution. As of late Friday night, no one had been found.
Authorities said the constructions who had been working on the building had left the site before the collapse.
The incident caused traffic backups and subway delays in the area.
Get Eyewitness News Delivered