A firefighter was killed and nine others were injured Friday when an explosion in suburban Washington leveled a home they had been called to for a gas leak. Two other people were also injured.

Firefighters were called to the home in Sterling, Va., after a report of the smell of gas shortly after 7:30 p.m., and the explosion occurred about 30 minutes later, officials said.

The explosion and fire occurred while firefighters were inside the building, James Williams, assistant chief of operations for the Loudon County Fire and Rescue Department, said at a news conference.

“Shortly after arriving, with firefighters inside, there was an explosion in the house,” Williams said.

One firefighter was killed, nine others, and two more people were taken to hospitals, some with serious injuries, Williams said.

“We have all the firefighters outside the building. The fire will continue to smolder,” Williams said, adding that the home was a “total loss.”