A 50-year-old woman died in a blaze inside a high-rise building in Brooklyn on Monday, officials said.

The fire broke out just before 2:45 a.m. on the sixth floor of 2475 West 16th Street, a 19-floor apartment complex in Gravesend, according to FDNY officials.

The woman, whose name was not immediately released, was rushed to Coney Island Hospital, but she could not be saved, cops said.

The cause of the fire remained unknown Monday afternoon. The city’s Fire Marshal is investigating.