A woman, who used an oxygen tank, died when her Bedford Stuyvesant apartment caught fire Monday night, police said.

Beverly Douglas, 65, was smoking a cigarette in her Gates Avenue bedroom when she suffered an apparent heart attack. Police said that she dropped the cigarette, which then caused the fire.

Douglas suffered from smoke inhalation, police said, and was found at about 10 p.m. She was taken to Woodhull Medical Center where she was pronounced dead.