What started as a high-profile military celebration near Camp Pendleton ended with a close call on one of California’s busiest freeways.
A California Highway Patrol (CHP) vehicle was struck by shrapnel on Oct. 18 after an artillery round exploded in midair over Interstate 5 during a live-fire demonstration by the U.S. Marine Corps. The event was part of the Marines’ and Navy’s 250th anniversary celebration that also brought Vice President JD Vance and Defense Secretary Pete Hegseth to the base.

A Flash Over the Freeway
According to an internal CHP report obtained by Military.com, the explosion happened around 1:46 p.m. Saturday. The round was fired from White’s Beach, about three-quarters of a mile south of Las Pulgas Road.
Moments after launch, it detonated before clearing the freeway. Small pieces of metal rained down near CHP officers who had been holding a traffic break to keep drivers clear of the area.
One officer said it sounded like pebbles hitting his motorcycle and the pavement around him. Another patrol SUV parked nearby was hit by a small piece of metal that left a dent on the hood.
No one was hurt, but the Marines immediately stopped all live-fire activity and ordered a full safety sweep of both sides of the highway. Traffic was reopened less than an hour later once the area was cleared.

CHP Chief: “Unusual and Concerning”
“This was an unusual and concerning situation,” said CHP Border Division Chief Tony Coronado in a statement. “It is highly uncommon for any live-fire or explosive training activity to occur over an active freeway.
"As a Marine myself, I have tremendous respect for our military partners, but my foremost responsibility is ensuring the safety of the people of California and the officers who protect them.”
Vice President Nearby During the Incident
CHP’s Protective Services Detail had escorted Vance to Camp Pendleton earlier in the day for the anniversary event.
His motorcade had already left the immediate area before the explosion. Officials said he was never in danger.
Call for a Safety Review
In its report, the CHP recommended a full after-action review to look at how the event was planned and coordinated between federal, state and local agencies. The agency said better communication and clearer safety zones should be part of future training or demonstrations that take place near public infrastructure.
Live-fire exercises over civilian areas are extremely rare. The mishap highlights the fine line between maintaining combat readiness and keeping nearby communities safe.

The Marine Corps canceled the rest of the exercise and began its own internal safety review.
Camp Pendleton referred Military.com to I Marine Expeditionary Force for comment. A response was still pending at press time.