A gunman attacked a grocery store in an upscale Tennessee suburb on Thursday afternoon, killing one person and wounding 12 others before he was found dead of an apparent self-inflicted gunshot wound at the store, authorities said.

Collierville Police Chief Dale Lane said the shooting broke out at a Kroger grocery in Collierville, a suburban community 30 miles (50 kilometers) east of Memphis. He said the gunman shot 13 others and himself, and that 12 of the victims were taken to hospitals, some with very serious injuries.

Kroger worker Brignetta Dickerson told WREG-TV she was working a cash register when she heard what at first she thought were balloons popping.

“And, here he comes right behind us and started shooting,” Dickerson said. “And, he kept on shooting, shooting, shooting. He shot one of my co-workers in the head and shot one of my customers in the stomach.”

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Lane said police received a call about 1:30 p.m. about the shooting and arrived almost immediately, finding multiple people with gunshot wounds upon entering the building.

He said a police SWAT team and other officers went aisle to aisle plucking panicked people from hiding and taking them out safely. He said the shooter, whom he described as male, was found dead of an apparent self-inflicted gunshot.

“We found people hiding in freezers, in locked offices. They were doing what they had been trained to do: run, hide, fight," the chief said.

The identities of the shooter and the victims were not immediately released. Lane declined to reveal more about the suspect at a news briefing Thursday evening, citing the ongoing investigation and search warrants that will be carried out.

“We're going to carry this thing as far as we can to see and make sure that there's no else involved,” Lane said, adding that there was “no credible evidence” that there was a second shooter.

The chief also said that, “As far as we know there wasn’t any other incident that led up to this.”

Dickerson, the employee, said her co-worker, who is in his 20s, was shot in the head and asked for his mother to be notified.

“I left her a voicemail that he was alert and talking,” Dickerson said, unable to immediately reach her.

Another employee, Glenda McDonald, described the chaotic scene to WHBQ-TV.

“I was walking back towards the floral department and I heard a gunshot,” she said. “It sounded like it was coming from the deli. And I ran out the front door and they had already shot the front door.”

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Jason Lusk, 39, had just left a tool store beside Kroger when he heard some women screaming in the parking lot about a shooter. He didn't see the gunman, but heard 10 to 15 rounds in rapid succession at the grocery store.

“It sounded like they were directly over my head," he said, adding he could feel the concussion of every shot and knew the weapon was powerful. Even at a distance of some 40 yards, he said, he worried that he and others around him were in grave danger.

“As the firing started, I dove in front of my vehicle onto the ground to provide the most cover for myself and instructed the people around me panicking, trying to get into the cars, not to get in their cars, but to actually hide," he said.

Then police arrived within minutes and “they swarmed that place," Lusk said. He added that he used his phone to record at least two of the gunman's final shots, and then a final gunshot on his last recording of the SWAT team on the scene.

At a new briefing afterward, the police chief Lane called it a sad day for his department.

“I've been involved in this for 34 years and I’ve never seen anything like it," he said.

The suspect’s vehicle was in the store’s parking lot and remained part of the investigation, the chief said, adding investigators were trying to determine how events unfolded.

“Let’s get through the investigation,” Lane said. "Remember, we’re two hours away from the most horrific event that’s occurred in Collierville history.”

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Collierville is a growing suburb of more than 51,000 people with a median household income of about $114,000, according to U.S. census figures. Set in a rural and historic area, the town square has largely become known for its boutiques and bed and breakfasts.

Earlier this year, Tennessee became the latest state to allow most adults 21 and older to carry handguns without first clearing a state-level background check and training. The measure was signed into law by Republican Gov. Bill Lee over objections from some law enforcement groups and gun control advocates concerned the measure would possibly lead to more gun violence.

The Kroger Co., based in Cincinnati, Ohio, issued a statement that it was "deeply saddened" by the shooting and was cooperating with law enforcement. The company in 2019 asked its customers not to openly carry guns while visiting its stores.

A Kroger spokesperson said the Collierville store will be closed until further notice.

Lights were still on in the store after nightfall, chrysanthemums set out front. The parking lot, entirely roped off with police tape, was still full of cars, with a heavy police presence. Neighboring businesses, including a fast food restaurant and an auto parts store, were closed.