A patrol vehicle was struck by shrapnel from an artillery round that was fired during Saturday's event at Camp Pendleton, officials said.

CAMP PENDLETON — Ordnance fired over the 5 Freeway at Saturday’s 250th anniversary of the Marine Corps at Camp Pendleton prematurely detonated, striking and damaging a California Highway Patrol vehicle that was part of Vice President JD Vance’s detail, the CHP said Sunday.

Marines are investigating after a 155mm artillery round exploded over Interstate 5, hitting California Highway Patrol vehicles with shrapnel.

Traffic delays could be significant Saturday with the U.S. military planning to fire live artillery rounds over Interstate 5 in Southern California. The freeway will be shut down temporarily Saturday afternoon.

The military showcase has drawn has drawn strong objections from Gov. Newsom, who said safety concerns forced him to close a 17-mile portion of the interstate.

The 5 Freeway, a major artery in Southern California, closed for a live-fire event at Camp Pendleton in northern San Diego County that was attended by Vice President JD Vance.

Vice President JD Vance celebrated the 250th anniversary of the United States Marine Corps on Saturday at a California event that drew some pushback from Gov. Gavin Newsom over a live artillery demonstration.

Vice President JD Vance joined with Marines from Camp Pendleton at the beach to observe a beach assault and celebrate the Marine Corps' 250th birthday on Saturday (Nelvin C. Cepeda / The San Diego Union-Tribune) Commandant of the U.