CHICAGO, July 11 (Xinhua) -- One firefighter was killed and some others were injured in a gas line explosion which severely damaged nearby buildings, authorities in U.S. Wisconsin state confirmed on Wednesday.

"Our thoughts and prayers are with the Sun Prairie Fire Department and the family of the fire fighter who died yesterday in the gas explosion in downtown Sun Prairie," Dane county sheriff's office tweeted.

Family and friends have identified the firefighter that was killed as Cory Barr.

Four other firefighters, a police officer and seven civilians were injured in the explosion, said local police Lt. Kevin Konopacki.

One of the injured firefighters was reportedly in critical but stable condition.

The explosion happened on Tuesday night in Sun Prairie, a suburb of state capital Madison, when firefighters were responding to a gas leak situation.

Kimberly Edlund, a resident who was just one block away from the explosion, said she first smelt a "strong gas odor," and ten minutes later, the blast happened, sending flames and a plume of smoke into the air.

At least two buildings were leveled and some cars parked nearby were destroyed, television footage showed.

Residents in a half-mile (800 meters) radius around the center of the explosion were ordered to evacuate, and displaced people stayed overnight at local schools.

Utility workers later successfully shut down the gas lines to contain the leak and prevent any further explosions.

There was reported ongoing construction in the area before the blast. Officials with WE Energies said they have been made aware of an independent contractor hitting a natural gas main, probably causing the gas leak and explosion.