Wayne Township fire officials on Tuesday released surveillance video that shows an explosion that gutted a vacant building on Indianapolis’ west side Monday evening. The footage came from a Kmart store across the street from the building in the 6900 block of West Washington Street that once housed a doughnut shop. The blast happened just before 6 p.m., startling customers inside the store and at other businesses in the area. "Fire investigators believe that a gas leak in the building is what caused the explosion," said Mike Pruitt, division chief of the Wayne Township Fire Department.