In a public service announcement filmed at his school in Austin last year, Zarriel Trotter talked about how violence was wreaking havoc on his West Side neighborhood.

“I don’t want to live around my community, where . . . people keep on getting shot, people keep on getting killed,” Zarriel, now a seventh-grader at Catalyst Circle Rock Charter School, says in the video.

Saturday night, the 13-year-old was in critical condition at Mount Sinai Hospital, under sedation and recovering from surgery after being shot by a stray bullet the night before.

“We’re all praying he stays strong,” his school’s principal, Elizabeth Jamison-Dunn, said.

Around 8:30 p.m. Friday, Zarriel was outside in the 5500 block of West Jackson Boulevard. Two groups were fighting down the street, and someone started shooting, catching him in the lower back, according to the police, who said he wasn’t the intended target.

No one had been arrested by Saturday night.

Zarriel underwent surgery Friday night, Jamison-Dunn said.

The principal said she always looks forward to Zarriel’s huge smile and his handshake when he arrives at school with his younger brother, a third-grader. She said he never misses an opportunity to shoot baskets during free periods and for the past two years has taken part in a male mentoring program with community leaders.

“He’s got this positive energy that’s contagious,” she said. “He can make your day.”

Zarriel is Austin’s 71st gunshot victim this year, and the second-youngest one, according to data gathered by the Chicago Sun-Times. A 12-year-old boy was among four teens wounded in a shooting earlier in the week about a block west of Circle Rock Charter School.

One of Zarriel’s Circle Rock classmates was shot and wounded about three years ago as a fourth-grader, according to Jamison-Dunn.

“It’s devastating when you see your students hurt,” she said. “They’re our kids, too.”