FARMINGTON, Maine — A police chief says a fast-thinking maintenance manager saved lives by evacuating employees before a building was leveled by a propane explosion that left him gravely injured.

Farmington, Maine, Police Chief Jack Peck says the disaster could have been a “more horrific tragedy” if Larry Lord hadn’t emptied the building of a dozen or so workers when gas was detected.

The explosion Monday leveled the two-story building that housed a nonprofit that serves people with cognitive and intellectual disabilities.

One firefighter was killed. The fire chief, five other firefighters, an ambulance worker and Lord were all injured.

Lord and three firefighters remain in critical condition at hospitals in Boston and Portland.

Investigators are working to pinpoint the cause. The blast also destroyed some nearby mobile homes and displaced about 10 people.

(AP)