A firefighter was killed and at least seven more people were injured when a building in Maine housing a center for people with disabilities exploded Monday morning.

The Farmington Fire Department responded a call about a “gas smell” at the administrative building for Life Enrichment Advancing People (LEAP), an organization that helps disadvantaged and disabled adults, just after 8 a.m., according to a statement from the Farmington Police Department.

“Upon arrival and while investigating the scene, the building exploded,” the statement said.

One firefighter was killed, and seven other people, including four firefighters, a LEAP maintenance worker and a NorthStar ambulance employee, were injured, according to police. The extent of the injuries was not immediately known.

“Our hearts go out to anyone injured or impacted today,” said a LEAP statement.

Multiple homes in the area were damaged, and the LEAP building was “totally destroyed,” police said.

Select Board Member H. Scott Landry said the building, which was recently renovated, was reduced to a hole in the ground.

“The new building is spread all over creation,” he told The Associated Press.

Chief of Police Jack Peck said the explosion was so strong that people in the adjacent town of Wilton could feel it. Investigators say it might have been caused by a propane or natural gas leak.

He told NBC News that five minutes before the eruption, children were being picked up from a bus stop in front of the building.

Gov. Janet Mills said she was monitoring the incident.

“Our hearts go out to all those impacted by this tragedy, especially to the loved ones of the firefighter lost and others injured. I am grateful for the work of first responders who are at the scene and urge Maine people to avoid the area,” Mills said in a tweet.