Authorities in Hobart, Ind., responded Sunday night to a shooting outside a Walmart that injured two and sent shoppers fleeing into the store for cover, reports said.

The Chicago Tribune reported that police have identified a person of interest. They believe the shooting was an isolated incident at the supercenter along U.S. Route 30.

Heidi Badgley, who was in the cat food aisle with her teen daughter, described a chaotic scene. She told the paper that she heard some kind of commotion and then saw people running.

“I mean running,” she said. “Crazy running.” After the scene calmed down, she approached her car and found a bullet hole in her bumper, the report said.

ABC 7 Chicago reported that the shooting appeared to start after an argument in the parking lot. Officers responded at about 7:37 p.m. to reports of gunfire. There have been conflicting reports of a second shooter, but authorities said there was a “single” gunman.

Several law enforcement agencies are investigating.