A 37-year-old man was killed on the Pomona (60) Freeway in Riverside, where he may have darted into traffic, authorities said Wednesday.
There were no details available about why the man was on foot on a busy freeway.
The fatality happened at 11:15 p.m. Tuesday on the eastbound 60 at Orange Street, according to the California Highway Patrol.
The agency said the victim, identified only as a Riverside resident, was hit in the No. 3 lane of the freeway, but it was unclear whether he ran into traffic or jumped from the Orange Street overpass.
A tractor-trailer may have run over the man, as well as other vehicles, witnesses told the CHP.
Riverside Fire Department crews reached the location within 15 minutes and pronounced the victim dead at the scene.
The eastbound 60 was partially shut down for four hours.
The investigation is ongoing.
Anyone with information was asked to contact the CHP Riverside office at 951-637-8000.