Update: Two men arrested and three victims identified. Story here.

One customer was there to buy a replacement battery part for a motorcycle. Another was picking up a tire for a friend. In an instant, the bystanders found themselves in the midst of a North Charleston shooting that killed three men on Saturday afternoon.

“It sounded like a whole magazine being emptied to me. Ten to 15 shots probably,” said Kevin Kerns of Ladson.

Kerns, 55, said he had just started to make the turn into Cycle Gear on Dorchester Road when gunfire burst out.

“I heard the shots. I saw guys going down,” he said.

Four men were wounded. The gunman had run back into the store, Kerns said. Although concerned for his safety, Kerns raced to the injured.

“My instinct to help took over,” he said.

Police arrived, and Kerns said he hollered to them about the shooter.

“They told me to take cover and help the guy as best I could,” he said.

He checked two men slumped on motorcycles who appeared dead to him.

“No pulse, no breathing,” he said.

Nearby, two people administered CPR to a man.

Police said they detained a suspect at the scene.

The shots were fired at about 4 p.m. during some type of altercation in the Cycle Gear parking lot, police said.

One gunshot victim died at the scene and two others died enroute to the Medical University of South Carolina. A fourth victim was treated by EMS for a non-life-threatening gunshot wound, police said.

A man who did not want to give his name nearly broke down in tears, describing what it was like being inside the store during the incident. At first, a fist fight broke out. Then the scuffle moved outdoors. About a dozen shots were fired.

“It was bad, man. It was bad,” he said.

He said that he took shelter behind the cash register.

Larry Guo said he was working at his Asian restaurant when police told him he was in danger.

“They told us to get out of the building and run to a safe place. Oh, my gosh, I was shocked,” he said.

The crime scene next to Brentwood Plaza drew a large crowd of onlookers, but few of them had anything to say about what had happened. Officers held up a blue tarp to shield the bodies of the dead from view.

“It’s just such a tragedy,” one man said.

Among those watching the police work was Charles Parker, who said he recently moved to North Charleston from Maryland.

“I guess I’m going to be getting my gun permit because I’m not going to be moving to the area and endangering my family,” he said.

Les Edmonds, who lived nearby, said Cycle Gear was a popular gathering spot on weekends.

“It’s packed every Friday and Saturday. There’s never been a problem like this around here,” he said.

The Charleston County Coroner’s Office had not released the names of the dead by late Saturday.