SAN DIEGO—A pedestrian was seriously injured Saturday by a hit-and-run driver after the victim laid down in the road in the Rolando neighborhood, police said.

The injury took place at 4:56 a.m. Saturday in the 6300 block of El Cajon Boulevard, according to Officer David O'Brien of the San Diego Police Department.

A vehicle of unknown description struck the pedestrian, who was lying in the street, the officer said.

“The driver of the vehicle stopped and assisted the pedestrian out of the road,” O'Brien said. “The driver then fled the scene.”

The pedestrian was rushed by ambulance to a local hospital, where he was treated for serious injuries.

Officers from the police department’s Traffic Division were investigating the incident.