By Vi Nguyen

CHICAGO (CBS) — Two high school seniors and a third person were shot when a gunman opened fire on their car Wednesday night on the South Side. One of them did not survive.

Police said the victims were driving south on Lafayette Avenue shortly before 10 p.m., when a white sedan pulled up, and someone inside started shooting, wounding three people in the car.

The victims kept driving, and stopped near 74th and Stewart, where police and paramedics were called to the scene. Investigators found at least 18 shell casings on the street where the victims were shot.

A 17-year-old boy was taken to the University of Chicago trauma center with a gunshot wound to the head. He was later pronounced dead.

An 18-year-old male also was taken to the University of Chicago. He was in critical condition with a gunshot wound to the back.

A third victim took himself to the University of Chicago with a gunshot wound to the chest. His age and condition were not available Thursday morning.

Community activist Andrew Holmes said one of the victims was making a phone call at the time of the shooting.

“One of the individuals was on the phone with his mother, and letting them know that someone was shooting at the car,” he said.

No one was in custody Thursday morning. Area South detectives were investigating.