A portion of the Southeast corner of the Rayburn House Office Building remains closed as Capitol Police assess the damage caused by a small fire that occurred on the roof of the building earlier this morning.

The fire was started by sparks from a welding machine being used by construction workers on the roof of the building.

At about 5:30 a.m. the building was evacuated after an odor of smoke was detected, and Capitol Police called in D.C. Fire and rescue teams.

Approximately 15 fire, EMS and command vehicles responded to the call, and the smoke smell was traced to a burned-out ventilation fan motor in the building.

But, according to D.C. Fire Department spokesman Alan Etter, during the course of their investigation, firefighters also found that sparks from metal cutting implements being used on the roof had found their way underneath the Rayburn ceiling and had started a small fire near the building’s Southeast corner.

Infrared cameras were used to locate the fire, and part of the wall was pulled out for firefighters to reach and put out the fire. Etter said the fire was out by 7:30 a.m., and there were no injuries.

By 8:30 a.m. most of the building was reopened, but Capitol Police spokesman Michael Lauer said that cleanup and damage assessment will keep the Southeast portion of the building closed until midnight tonight or early Friday.

— John McArdle