San Diego Fire-Rescue Department was called to Jefferson and Rosecrans streets around 8 p.m. after witnesses said a Toyota Tundra pulling a jet-ski was dangling off the edge of southbound I-5 near Old Town.
A witness told California Highway Patrol officers that a man ran from the crash and an 18-month-old boy was left strapped inside the dangling vehicle.
Witnesses described the suspect as a man in his 30s wearing a white shirt, black shorts and sandals. CHP officers said they are searching for the registered owner of the pickup.
The child was transported to Rady Children’s Hospital for treatment of severe head trauma, according to reports. His current condition was not known.