UPDATE Wednesday - 2/6/2013, 4:31pm ET - D.C. Fire officials said Wednesday that firefighters found the two victims inside the abandoned building while they were battling the blaze.
The victims are a man and a woman. They have been taken to the Office of the Chief Medical Examiner to be identified. Autopsies are pending.
Fire investigators continue to probe what caused the fatal fire.
UPDATE Tuesday - 2/5/2013, 4:45pm ET - The District's first fatal fire of the year killed two adults and displaced nine families.
The fire broke out in an abandoned, two-story apartment building at 1704 R. St. SE.
The displaced families lived on either side of the abandoned building. Their homes were not damaged but they were displaced as a precaution, fire officials say.
Fire spokesman Lon Walls says two firefighters suffered minor shoulder injuries and a third firefighter broke his ankle fighting the blaze.
The cause of the fire remains under investigation.
Tuesday - 2/5/2013, 12:10pm ET - WASHINGTON - Two people are dead and two firefighters injured after a fire in Southeast D.C. Tuesday morning.
Investigators are looking into what started the fire inside an apartment building in the 1700 block of R Street Southeast.
The firefighters injuries are not life threatening, says a fire spokesperson.
Follow @WTOP on Twitter.
(Copyright 2013 by WTOP. All Rights Reserved.)