During a live-fire military demonstration commemorating the 250th anniversary of the U.S. Marine Corps, shrapnel from an artillery round prematurely detonated and struck a California Highway Patrol (CHP) vehicle along Interstate 5 near Camp Pendleton, San Diego County, authorities reported.
The event, held Friday evening and continuing into Saturday, was a large-scale simulation intended to display Marine Corps capabilities, including high explosive rounds fired from M777 Howitzers—artillery pieces well known for their use in recent conflicts such as Afghanistan and Ukraine. The demonstration included a staged beach assault and drew an estimated 15,000 spectators, including Vice President JD Vance, who attended and delivered a speech.
While military officials had initially assured the public and California authorities that all safety precautions would be observed and that live munitions would only be fired into designated training ranges at Camp Pendleton, operational decisions upended these assurances. Federal officials explicitly stated that no public highways would need to close for the event. However, California state officials expressed strong concerns about firing artillery rounds over the heavily traveled Interstate 5, which runs directly between the beach assault site and the inland portions of the military base.
Despite these concerns, Marines conducted an unannounced test firing on Friday evening, discharging artillery rounds over the freeway without prior notification to state authorities, a move criticized by Governor Gavin Newsom’s office. The California Department of Transportation recorded video of the live-fire tests, further validating the uncommunicated activity.
Following this, officials temporarily shut down a 17-mile section of Interstate 5 between just south of San Clemente and north of Oceanside on Saturday to allow the rest of the event to proceed safely. The freeway usually services more than 80,000 vehicles daily.
However, the demonstration did not conclude without incident. The California Highway Patrol confirmed that a cruiser parked on an onramp was struck by falling shrapnel when an artillery round exploded prematurely in midair—much earlier than planned. Fortunately, no injuries were reported, but the incident raised significant safety concerns about the proximity of live artillery fire to public highways. The event had to be ended early due to the unexpected detonation and subsequent danger to the public and military personnel.
The situation sparked critical questions from both the public and California officials regarding the wisdom of firing live artillery over a major interstate highway. Military officials had previously denied plans to fire mortar rounds over the freeway or any actions that would impact public roads. The premature explosion and the strike on the patrol vehicle contradicted these assurances, triggering scrutiny of the planning and communication surrounding the event.
Additional context to the event included simultaneous protests named ‘No Kings’ directed against former President Donald Trump and his administration, occurring throughout Southern California and nationwide. These protests ran concurrently with the military demonstration, adding a layer of public attention amid a politically charged environment.
The incident underscores the complex challenges of conducting live-fire demonstrations in close proximity to civilian infrastructure and emphasizes the importance of clear communication and stringent safety protocols between military operators and civilian authorities. Governor Newsom’s office highlighted the need for improved coordination following the incident and confirmed that state highway patrol officers would continue to advocate for public safety in such engagements.