SAN DIEGO – A 4-year-old boy suffered major injuries early Tuesday when he was struck by a pickup truck on an Interstate 15 offramp in the City Heights area, authorities said.

Dispatchers received a call shortly before 12:05 a.m. from someone who reported that a pedestrian had been struck on the University Avenue offramp from southbound I-15, California Highway Patrol Officer Jake Sanchez said.

The pickup’s driver saw the boy walking in the lanes on the offramp and veered left, but struck the boy as he tried to stop, it was reported.

It’s unclear why the boy was wandering alone near the highway.

The tot was taken to Rady Children’s Hospital in San Diego with major injuries, Sanchez said.

The 29-year-old man behind the wheel of the 2000 Chevrolet Silverado remained at the scene, and intoxication is not believed to be a factor in the accident, the officer said