Additional Coverage:
- Military report says ‘one in a million’ live fire malfunction rained shrapnel on California highway (cnn.com)
“One in a Million” Misfire Rains Shrapnel on I-5 During Marine Corps Celebration
SAN DIEGO, CA – A “one in a million” malfunction during a live-fire demonstration at Camp Pendleton last October resulted in an artillery shell prematurely detonating, raining shrapnel onto Interstate 5 and striking two California Highway Patrol vehicles, according to a recent U.S. Marine Corps investigation.
The incident occurred on October 18, 2025, during a celebration of the Marine Corps’ 250th anniversary, an event attended by Vice President JD Vance and Defense Secretary Pete Hegseth. While the roadway was closed for the demonstration, pieces of shrapnel from the exploding shell scattered, hitting a CHP patrol car and a motorcycle.
The day prior to the event, Democratic Governor Gavin Newsom had voiced concerns about the demonstration’s safety and necessity, even briefly closing a 17-mile stretch of I-5 – a key corridor between Los Angeles and San Diego – a move that drew criticism from the White House.
A 666-page report, dated December 19 and first reported on Monday, concluded that “there is no definitive answer” as to why an M795 high explosive round detonated early at an altitude of approximately 1,480 feet (450 meters). The report described such a premature detonation as “beyond reasonable expectations and should not have happened, but it did,” noting that the munition is manufactured with a tolerance of “one defect in a million.” Investigators found no evidence of negligence or wrongdoing by Marine Corps personnel, and thankfully, no injuries were reported.
In the aftermath of the malfunction, 26 California U.S. House members and the state’s two senators sent a letter to Secretary Hegseth, questioning the decision to fire live artillery over the freeway and the safety preparations undertaken.
The mishap further fueled existing tensions between President Donald Trump and California leaders, including Governor Newsom. Some Republicans initially criticized Newsom for the freeway closure ahead of the live-fire exercise, while other local leaders expressed exasperation over what they viewed as an unorthodox military display orchestrated for the benefit of Trump administration officials.
Diana Crofts-Pelayo, a spokesperson for Governor Newsom’s office, stated on Tuesday, “We’re thankful to the Marines for their thorough and precise investigation – in stark contrast to the dangerous and performative demands by JD Vance and Pete Hegseth to shoot live ammunition over a civilian area for their entertainment.”
Newsom had announced the highway closure after practice rounds were fired a day before the main celebration. At the time, the governor characterized the live-fire exercise as a show of force intended to intimidate Trump’s opponents, thousands of whom were participating in “No Kings” protests in and around San Diego that day. “Firing live rounds over a busy highway isn’t just wrong – it’s dangerous,” Newsom wrote.
The Marine report suggested several potential contributing factors to the malfunction, including the howitzer guns being positioned too close together when fired and the “potential presence of anomalous electromagnetic energy in the vicinity.”
The October 18 demonstration at Marine Corps Base Camp Pendleton showcased aircraft, ships, and amphibious assault vehicles as part of the anniversary commemoration. It was planned to involve the firing of 60 artillery rounds across the coastal freeway, according to an October CHP incident report.
“It will be a good show regardless of who shows up,” Gen. Eric Smith, commandant of the Marine Corps, wrote in an October 14 email to Brig.
Gen. Garrett “Rainman” Hoffman of the White House Military Office.
Military and public safety officials noted that this location for live fire was unusual, as training typically occurs on designated ranges within the 195-square-mile (505-square-kilometer) base north of San Diego.
The first round was launched at 1:46 p.m. from M777 howitzers on a beach west of Interstate 5, fired eastward. The artillery round failed to clear the roadway and detonated mid-flight near I-5 southbound, sending shrapnel towards protective service details assigned to the vice president. The exercise was immediately halted, and no further munitions were fired, as reported by CalMatters in October.
One officer described hearing what sounded like “pebbles” falling on his CHP BMW motorcycle, while other shards struck an empty Ford patrol car that was part of Vance’s motorcade. The two officers who had been in the car discovered a 2-inch by ½-inch piece of shrapnel on the hood, which left a small dent or scratch. Incident reports included photos of the patrol car struck by shrapnel and an officer holding the metal shards.
A December 5 statement cited in the military report, from a redacted Marine, indicated that the Secret Service had requested the closure of I-5 due to security concerns for a “Very Very Important Person” – the president – and the freeway’s proximity to a demonstration viewing area. President Trump ultimately did not attend the event.