Flames ripped through a two-story house in Anacostia Saturday night, claiming the lives of two women, a mother and a daughter.
The two-alarm blaze was located in the 1600 block of W street in Southeast Washington and began around 7:30 p.m. on Saturday.
Ruth Harris, 84, was pronounced dead at the hospital.
Her daughter, Dolores Harris, 59, was resuscitated on the way to the hospital, but died Sunday afternoon.
The intense conditions required extra firefighters to report to the scene. Two firefighters were taken to the hospital to be treated for heat exhaustion, and one firefighter suffered minor burns.
According to department officials, the blaze brought more than 100 fire and rescue personnel to the scene.
The cause of the fire remains under investigation.
Investigators found two smoke detectors in the house, but it was unclear if they were working.
Firefighters plan to return to the neighborhood Sunday to make sure residents have working smoke alarms.