A 38-year-old window washer fell five stories to his death Tuesday while cleaning a TriBeCa building, police said.

The man, who was not immediately identified, was cleaning the last window of 335 Greenwich Street, near Jay Street, from the inside at about 1:10 p.m. The unhinged window then swung open and the man, who was not wearing a harness, fell to the sidewalk, police said.

He was taken to New York Presbyterian where he was pronounced dead.

The incident was ruled an accident, police said.