A 100-year-old man hit 11 people—including nine children—with his car Wednesday just after classes at Main Street Elementary had let out for the day.

The car slowly backed into the group of parents and children buying snacks from a sidewalk vendor across the street from the school, reports the Los Angeles Times. The crowd banged on the car's windows and screamed for driver Preston Carter to stop, but some of the children became trapped under the car. Carter told television reporters later that his brakes had failed.

Carter mistaken backed his car onto a sidewalk while pulling out of a grocery store parking lot, police Capt. George Rodriguez said. Four of the children are in serious condition at a hospital, but everyone is expected to survive.