‘No one dared to flee’ as the shooter carried out his rampage.

Grace was in the back corner of the dance hall, practicing her steps, joining about 100 other patrons who know the Star Ballroom Dance Studio as the place to be on Saturday nights.

Many were facing the wall-length mirror, running through their own dance moves. On the speakers was the music for guangchang wu, a public square dance popular among middle-aged and older Chinese patrons, recalled Grace, a dance student in her 50s who had been coming to the Star Ballroom for about four years.

Then, suddenly, she heard a series of pops that sounded like fireworks.

She looked toward the entrance and saw people collapsing on the floor, and she dove under a table as others were frantically doing the same, she said. She could see the gunman and his two-foot-long weapon, she recounted.

“No one dared to flee — we all got down to the ground, hiding wherever we could,” she said in an interview Sunday afternoon, down the street from the Star Ballroom. She asked that she be identified only by her English first name because she didn’t want people in the community to know she was there at the time of the shooting.

“No one could get out,” she added.

A man she called “Ma laoban” — “Boss Ma” — was near the entrance and appeared to be the first one who was shot, she said. Two people who were next to him also collapsed as five or six shots occurred in rapid succession, she said.

He appeared to run out of bullets and quickly left before returning to unleash a second bout of gunshots deeper into the ballroom. Some people who appeared to have been shot were splayed out on the wooden floor; others ducked under a table or ran into a back room. The whole mass shooting lasted about five minutes, she said.

“I saw him, but I was far away and the lights were dim. I could not see his face clearly,” said Grace, who said she didn’t recognize the suspect in the photos released by local authorities Sunday morning while he remained at large.

The suspect fatally shot himself later Sunday in a parking lot about 30 miles away in Torrance as he was surrounded by the police, said Sheriff Robert Luna of Los Angeles County. The gunman was identified as Huu Can Tran, 72.

After the shooter left, several people called 911 and the police seemed to arrive swiftly, she recounted. They were taken to the police station in vans for detailed questioning about the suspect for hours, she said. Mr. Tran headed next to another ballroom dance studio in Alhambra, about three miles away, where two patrons wrested his gun away and the suspect fled on foot, Sheriff Luna said.

Grace said she didn’t get home until 3 a.m. Sunday and got only about an hour of sleep because her phone was ringing off the hook with calls from friends and acquaintances who knew she was a regular at Star, she said.

She clutched her heart, describing how scared and shaken she still felt a day after the shooting. She wasn’t sure whether she’d be able to return to the studio, where she said dancing had kept her happy and healthy, and where she had learned to dance her favorite, the waltz.

“It brings me joy. My instructor is very positive and he brings me joy, too,” she said. “Once the suspect is arrested, maybe after a period of time of healing, maybe I will go back.”

Angela Chen contributed reporting.