Shrapnel from artillery that was detonated during celebrations for the US Marine Corps hit at least two vehicles on a California highway on Saturday, officials have said.
The event, celebrating the Marines' 250th birthday, was attended by Vice President JD Vance, and included live munitions being fired. The California Highway Patrol said one detonated overhead prematurely and struck two vehicles that were part of Vance's protective detail.
It came as state officials and the White House fought over a decision to close part of Interstate 5 for the event in southern California.
Firing live rounds over a busy highway isn't just wrong - it's dangerous, Governor Gavin Newsom, a Democrat, said.
The highway patrol said no injuries were reported and they notified the Marine Corps, which then cancelled firing any further munitions.
This was an unusual and concerning situation, Border Division Chief Tony Coronado said in a statement, adding that such exercises are not common over an active freeway.
Newsom said he closed a section of the Interstate 5 due to extreme life safety risk and distraction to drivers, including sudden unexpected and loud explosions.
But before they were aware of the mishap, officials in the vice-president's office had disputed that the demonstration was dangerous, and accused the California governor of trying to stoke fears.
The incident was part of the largest military demonstration in a decade in the continental US, which involved fighter jets, Navy vessels, helicopters, and live fire from a towed howitzer. The First Marine Expeditionary Force at Camp Pendleton acknowledged the incident and stated an investigation is underway.
The demonstration concluded as scheduled but highlighted the complexities and dangers of military exercises during public events.
