A fire on Friday afternoon severely damaged the Columbia Heights home of a well-known pair of civic activists.

Firefighters responded at about 4:30 p.m. to the home of Dorothy Brizill and Gary Imhoff on the 1300 block of Girard Street NW. They found heavy fire on the top two floors of the three-story house, said Lon Walls, a fire department spokesman.

One firefighter was taken to a hospital with minor burns; no other injuries were reported. Neither Brizill nor Imhoff were home at the time, WRC-TV reporter Tom Sherwood tweeted. Brizill could not be immediately reached for comment.

The two-alarm fire forced firefighters to evacuate the home and later a wall collapsed inside, which caused a gas leak. The fire was under control in about an hour, but it continued to smolder as firefighters were forced to battle the blaze from outside the home, officials said.

Walls said the house was “wiped out,” speaking shortly after 7 p.m. “It’s a disaster, a total loss,” he said.

A witness, Chris Peterson, reported shortly after 6 p.m. that the roof and upper two stories of the facade were “gone,” with bricks strewn across the first-floor porch.

Brizill and Imhoff, under the name D.C. Watch, have been deeply engaged as local government watchdogs for more than two decades. Notably, Brizill in 2002 raised questions about ballot petitions submitted by former Mayor Anthony A. Williams, which led the Board of Elections and Ethics to strike his name from the Democratic primary ballot. Williams ended up winning as a write-in candidate. More recently, Brizill raised concerns about the voting record of a top aide to Mayor Vincent C. Gray (D), leading to her resignation.

Their home, built in 1870, has garnered the attention of city authorities in the past decade for its sometimes dilapidated condition. In 2002, the city placed it on a list of vacant and abandoned properties, though the couple was residing there at the time. In 2007, the Board for the Condemnation of Insanitary Buildings raised concerns about the home, eventually issuing a condemnation order, leading Brizill and Imhoff to replace windows and repair the porch.

There is no indication the fire was related to those issues.