Artillery round prematurely detonates during Marines display, damaging CHP vehicle
An artillery shell prematurely detonated over Interstate 5 during a Marine Corps anniversary celebration attended by Vice President JD Vance, sending shrapnel onto a California Highway Patrol vehicle and prompting intense criticism from Governor Gavin Newsom, who had opposed the live-fire exercise over safety concerns.
The incident occurred at approximately 1:46 p.m. on Saturday, October 18, 2025, during the Marine Corps’ 250th anniversary celebration at Camp Pendleton in San Diego County. The 155mm artillery round, fired from White’s Beach about three-quarters of a mile south of Las Pulgas Road, detonated mid-air over the closed freeway instead of reaching its designated impact zone.
Metal shrapnel from the premature explosion struck an unoccupied CHP patrol vehicle, leaving a small dent and scratch on the hood. The fragment that hit the vehicle measured approximately 2 inches by 2 inches. Additionally, a CHP motorcycle officer reported hearing what sounded like “pebbles falling” around him and later found a piece of shrapnel about an inch long and half an inch wide near his motorcycle, though the motorcycle itself was not damaged.
No officers were injured in the incident.
Political Tensions Over Safety
The mishap occurred amid a heated dispute between state and federal officials over the propriety of conducting live-fire exercises over a major transportation corridor. Governor Newsom had closed a 17-mile stretch of Interstate 5 for several hours during the celebration, citing “extreme life safety risk and distraction to drivers, including unexpected and loud explosions”.
In a statement posted to social media following the incident, Newsom sharply criticized the Trump administration:
“The president is putting his ego over responsibility with this disregard for public safety. Firing live rounds over a busy highway isn’t just wrong -- it’s dangerous. Using our military to intimidate people you disagree with isn’t strength -- it’s reckless, it’s disrespectful and it’s beneath the office he holds”
The freeway closure disrupted approximately 80,000 daily travelers and $94 million in freight traffic, according to the governor’s office. Passenger rail services operating parallel to Interstate 5 were also suspended during the event.
Military Response and Investigation
Following notification from CHP officers at 1:46 p.m., the Marine Corps immediately canceled the firing of additional live ordnance over the freeway. According to the CHP incident report, the Marines had originally planned to fire approximately 60 artillery rounds over a five-minute period, but the exercise was terminated after the premature detonation.
Captain Gregory Dreibelbis, a spokesperson for the Marine Expeditionary Force, confirmed that the Marine Corps is aware of “a possible airborne detonation of a 155 mm artillery round outside the designated impact area”. He stated that the demonstration had undergone “a thorough safety assessment, incorporating multiple layers of redundancy to ensure the safety of the public”.
“We are dedicated to uncovering the root cause of the incident and will apply our findings to future operations,” Dreibelbis added.
The Marine Corps maintained that live-fire training at Camp Pendleton is conducted continuously throughout the year to maintain combat readiness and that the exercise was both safe and properly planned.
Federal-State Coordination Concerns
Tony Coronado, Chief of the California Highway Patrol Border Division and a Marine Corps veteran himself, characterized the incident as highly unusual. “It is quite rare for any live-fire or explosive training to take place over an active freeway,” Coronado stated. “As a Marine myself, I hold great respect for our military partners, but my primary obligation is to ensure the safety of California’s residents and the officers who protect them”.
The CHP’s Border Division called for a formal after-action review “to strengthen communication and coordination between federal, state, and local partners during future demonstrations or training events near public roadways”.
Prior to the event, the Vance administration had contested Newsom’s safety concerns. William Martin, Vance’s communications director, asserted that the Marine Corps classified the exercise as “an established and safe practice” and a regular training activity at Camp Pendleton. Martin accused Newsom of misrepresenting the risks and attempting to “stop the training exercises that ensure our Armed Forces are the deadliest and most formidable fighting force in the world”.
The Celebration Event
The Marines described the “Sea to Shore” amphibious assault demonstration as the largest of its kind in the continental United States in ten years. The event featured fighter jets, helicopters, Navy ships, and live fire from a towed howitzer. Approximately 15,000 military personnel and dignitaries attended the celebration.
Vice President Vance, who served four years in the Marine Corps, including a tour in Iraq, attended alongside Defense Secretary Pete Hegseth to commemorate the Marine Corps’ founding on November 10, 1775. In his speech at the event, Vance reflected on his own Marine Corps service and criticized what he termed a government shutdown instigated by Democrats.
CHP officers swept both northbound and southbound lanes of Interstate 5 following the incident and found no additional shrapnel or hazards. The freeway was subsequently reopened.
Associated Press News. 2025. “Marine Corps shrapnel hits and damages a California Highway Patrol vehicle.” October 19, 2025. https://apnews.com/article/california-marines-live-fire-highway-6fde99346aeffc34cc12412709391269
CNN. 2025. “Shrapnel from Marines anniversary demonstration detonates over California interstate and hits squad car, highway patrol says.” October 19, 2025. https://www.cnn.com/2025/10/19/us/camp-pendleton-marines-demonstration-shell
Los Angeles Times. 2025. “How military’s ‘safe’ plan to fire munitions over Interstate 5 went off the rails with CHP cruiser hit.” October 20, 2025. https://www.latimes.com/california/story/2025-10-20/camp-pendleton-live-fire-interstate-5-shrapnel
NBC News. 2025. “Patrol vehicle hit by shrapnel as Marines fired live artillery in California.” October 19, 2025. https://www.nbcnews.com/news/us-news/patrol-vehicle-hit-shrapnel-marines-fired-live-artillery-california-rcna238550
The Washington Post. 2025. “Artillery shell detonates over I-5 during Marine exercise attended by Vance.” October 20, 2025. https://www.washingtonpost.com/nation/2025/10/20/marine-exercise-trump-newsom-shell-interstate/