A man was injured by an explosion after he put gasoline instead of detergent into a washing machine, police said.

The explosion Saturday blew off the door to a laundry room in the man's apartment in the Summit-University neighborhood, Deputy Chief Mike Hogan said. There was no damage to the six apartment units in the building or other injuries.

The 49-year-old man had what appeared to be second-degree burns on up to 5 percent of his lower legs, Hogan said. Paramedics took him to Regions Hospital.

Described by neighbors as a "backyard mechanic," the man was using gasoline to wash his grease-soaked clothes for some reason and "didn't think anything of it," Hogan said. The hot water heater or another source ignited a fire that led to the explosion, he said.