Vice President JD Vance spoke to about 15,000 people at Camp Pendleton on October 18, 2025. The event celebrated the Marine Corps’ 250th anniversary.
This large 125,000-acre base on the California coast hosted an important event to show American military strength. Federal officials promised that strict safety measures would be in place during the activities. However, tensions were already rising with state leaders about the extent of the planned events.
Safety Assurances
On October 13, Marine Corps officials reassured the public that “no public highways or transportation routes will be closed” for the live-fire exercises. They stated that all activities will follow safety protocols and take place in designated training areas.
Governor Gavin Newsom’s office first called this idea “an absurd show of force.” However, by Thursday morning, the state confirmed that no artillery rounds would be fired over Interstate 5.
The M777 System
The M777 Howitzer has been a key part of Marine Corps artillery since 2005. It fires 155mm shells that weigh about 100 pounds and are around two feet long, with a range of up to 25 miles.
According to the Associated Press, it is one of the most requested weapons in Ukraine’s defense efforts. U.S. Marines have used the M777 in places like Syria and Afghanistan, often firing over friendly troops to hit enemy targets.
Friday Rehearsal
On the evening of Friday, October 17, state officials found that M777 Howitzers had fired shells over Interstate 5 from Red Beach without notifying California authorities. The California Department of Transportation recorded the unannounced drill on video as cars passed underneath.
Marines later confirmed that the firing was part of their regular preparation, stating that artillery had “historically been fired” from west of I-5 toward target areas on the east side “without the need to close the route.”
Premature Detonation
On Saturday at 1:46 PM, an M777 artillery round fired from White’s Beach exploded in the air Interstate 5, earlier than expected. Metal pieces, some as big as 2 inches by 2.5 inches, hit a parked CHP cruiser on the Las Pulgas Road on-ramp, causing a dent and scratch.
Other debris landed within three feet of a nearby CHP motorcycle officer. The Marines immediately canceled the remaining 59 artillery rounds scheduled for that day.
Freeway Paralysis
Earlier that day, Governor Newsom ordered a 17-mile section of Interstate 5 to be closed. This stretch, from just south of San Clemente to just north of Oceanside, closed at 1:15 p.m. and reopened around 2:20 p.m.
As a result, travel times between Los Angeles and San Diego increased to three hours, which is about an hour longer than usual for a Saturday. Electronic signs along the freeway warned drivers: “Live weapons over freeway.” This closure caused traffic problems across Southern California’s coastal areas.
Officer Response
CHP motorcycle officers heard sounds like “pebbles falling” when metal shrapnel fell around them. One officer found a one-inch piece near his bike after escorting Vice President Vance to the event.
Thankfully, no one was hurt. At 1:55 PM, CHP searched I-5 for safety and found two pieces of debris. They cleared the freeway and reopened it in less than an hour.
Political Flashpoint
The situation quickly became a political issue. Just after 11 AM on Saturday, the White House Rapid Response Team criticized Governor Newsom on social media, saying “nobody at the White House or the Marines asked him” to shut down the freeway.
They emphasized that “the Marines repeatedly said there are no public safety concerns.” After the shrapnel incident, Newsom fired back, accusing President Trump and VP Vance of putting “lives at risk to put on a show.” What started as a safety debate had now escalated into a full-blown clash between state and federal leadership.
Collateral Disruptions
The freeway is closed, and federal officials have also stopped Amtrak and Metrolink services along the tracks next to Interstate 5 through Camp Pendleton. Pacific Surfliner service was suspended from noon to 3 PM on Saturday.
The White House Production Office was filming a demonstration for a primetime special called “Sea to Shore — A Review of Amphibious Strength,” scheduled to air on November 9. The explosion happened during filming, and it is unclear if any footage will be shown.
Reliability Shattered
Col. Lindsay Pirek, spokesperson for the First Marine Expeditionary Force, told the Los Angeles Times that the round that exploded was one of five fired in the first attack.
She said the M777 cannon had previously worked perfectly without any failures. Since this weapon is used in combat to fire over friendly forces, the early detonation is a serious concern.
Chief Coronado
CHP Border Division Chief Tony Coronado, a Marine Corps veteran himself, faced a difficult balancing act—standing up for public safety while respecting his former service branch. “As a Marine myself, I have tremendous respect for our military partners,” Coronado said.
“But my foremost responsibility is ensuring the safety of the people of California and the officers who protect them.” His comments captured the tension between honoring military tradition and upholding civilian oversight.
Expert Analysis
Carlton Haelig, a fellow at the Center for a New American Security, warned that firing live artillery over crowds or infrastructure carries risks, even when systems are well-designed.
“A premature explosion or similar incident would raise significant concerns regarding shrapnel in populated regions,” Haelig said. The incident sparked broader concerns over whether the spectacle was worth the danger of deploying high-explosive rounds above an active freeway.
Planning Failures
The Friday rehearsal exposed gaps in coordination. California’s Department of Transportation only learned about it after capturing the artillery fire on video.
While Col. Pirek later told reporters that artillery is “not frequently fired” at Camp Pendleton and that firing over I-5 is “extremely rare,” this conflicted with an earlier statement from Captain Dreibelbis, who said, “Marines fire artillery at Camp Pendleton nearly every week.” Notably, base maps show no designated artillery zones along the beach west of the freeway, raising questions about why that firing position was used at all.
Response & Investigation
“We love our Marines and owe a debt of gratitude to Camp Pendleton,” Governor Newsom wrote after the incident. “But next time, the Vice President and the White House shouldn’t be so reckless with people’s lives for their vanity projects. This could have killed someone.”
The Marine Corps has launched a formal investigation to determine the root cause of the incident. Investigators are examining whether a fuse malfunctioned, if firing data was incorrectly calculated, or if environmental conditions may have contributed to the incident.
Precedent Set
Following the incident, the California Highway Patrol filed an internal report recommending a thorough after-action review focused on improving coordination among federal, state, and local agencies. According to CHP records, this marks the first known instance of live artillery being fired over Interstate 5.
With other military bases preparing anniversary events in the coming years, the mishap at Camp Pendleton may influence how such displays are handled—especially when civilian safety is at stake.