Decatur, AL – DECATUR, Ala.

A man was critically injured Sunday in an early morning explosion at a Decatur house.

The victim, Steven Foster Sheffield, 40, was in critical condition at the University of Alabama at Birmingham burn center with second and third degree burns over approximately 60 percent of his body.

Foster told police he was entering the home at about 2 a.m. Sunday and the house exploded when he turned on a light switch, police Lt. John Bradford said.

Decatur Fire Marshal Dwight Walden said Sheffield suffered severe burns.

Walden said investigators believe the explosion was caused by natural gas. But he said it has not been determined what ignited the gas