A 26-year-old man was killed Friday when for unknown reasons he tumbled out of the car he was riding in on Interstate 8 near Grossmont Center mall, authorities reported.
The man fell out of the westbound Audi A4 in the area of Severin Drive in La Mesa shortly before 11 a.m., according to the California Highway Patrol.
After landing on the roadway, a tractor-trailer ran over him, killing him at the scene, CHP public-affairs Officer Jared Grieshaber said.
It was not immediately clear how or why the man, a Santa Ana resident whose name was withheld pending family notification, exited the moving vehicle.
City News Service contributed to this article.