A window washer plunged to his death while working on a Brooklyn high-rise under construction, police said.

Diego Rodriguez Celi, 34, of NJ, fell from the 12th floor of the condo being built on York St. near Bridge St. in DUMBO on Friday morning, authorities said.

He landed on a second-floor balcony, according to cops.

Officers responded to a call around 8:30 a.m. and discovered Celi unconscious, with injuries “indicating he had fallen from an elevated position,” police said.

He was pronounced dead at the scene, authorities said.

No cause has been released for the fall.

The incident is under investigation by the NYPD and the city’s Department of Buildings.