One firefighter was killed and 11 other firefighters and two civilians were injured in a massive home explosion in Northern Virginia's Loudoun County on Friday night, officials said.

In a news briefing Saturday morning, Keith Johnson, the chief of Loudon County's Combined Fire and Rescue System, said 911 operators received a call about a gas odor in the area of Sterling, Virginia, at around 7:30 p.m. Crews arrived on the scene at around 7:50 p.m. and found a 500-pound underground propane tank leaking, Johnson said.

The propane from the leak had "migrated into the home," Johnson said. Firefighters assessed the situation, evacuated the home's owners and pets, and entered the home.

A "catastrophic explosion" occurred at 8:25 p.m., Johnson said. Multiple mayday calls were reported for firefighters trapped inside the structure, Johnson said, with others outside the home injured as well.

"Soon after arrival, with firefighters inside, the house did explode," Loudoun County Fire and Rescue Assistant Chief of Operations James Williams said Friday. Aerial footage from CBS affiliate WUSA-TV showed widespread debris from the explosion, with heavy flames burning and smoke billowing hundreds of feet into the air. Johnson said Saturday that there was "significant damage" to the house. Other homes in the vicinity also had some damage, he said. 

Ten firefighters were taken to local hospitals. Both of the home's occupants also had minor injuries, Johnson said. As of Saturday morning, four members of the fire system were still in the hospital "in varying levels of injury," Johnson said. All four are expected to survive.

The firefighter who was killed was identified Saturday morning as Trevor Brown, 45, who worked with the Sterling Volunteer Fire Company. He had been affiliated with the county fire and rescue system since 2016. Brown is survived by his wife and three children, Johnson said. An autopsy to determine his cause of death will be conducted, Johnson said.

"In a sense, we lost a family member. We lost one of our own," Johnson said. A team from the county fire and rescue system is supporting Brown's family, Johnson said, and helping plan his funeral in accordance with the family's wishes. 

The fallen firefighter from last night’s home explosion in Sterling has been identified as Firefighter Trevor Brown, 45,...

Posted by Loudoun County Fire and Rescue on Saturday, February 17, 2024

Johnson said it was a miracle that only one firefighter was killed in the explosion.

An origin and cause investigation into the explosion will be conducted by the fire marshal's staff, Johnson said. He said that he can assume it was "propane-related," but no cause has been identified yet.

Another incident investigation team, of external fire and rescue officials, will take an "objective look" at the response to the explosion, Johnson said. 

Johnson urged anyone who smells gas to call 911, saying that the home's residents are alive today because they did so. The propane tank was isolated to the home, so they are not expecting a widespread problem.

Local utility provider Washington Gas said in a statement to CBS News that it was "verifying the integrity of our system in the surrounding area," but Johnson said that as far as he was aware, the propane was not supplied by Washington Gas. The company that supplied the propane, which Johnson declined to name, will be looked at as part of the investigation, he said. 

Sterling is located about 25 miles northwest of Washington, D.C.

In:
• Fire
• Explosion
• Virginia

Faris Tanyos

Faris Tanyos is a news editor for CBSNews.com, where he writes and edits stories and tracks breaking news. He previously worked as a digital news producer at several local news stations up and down the West Coast.