An explosive ordnance detonated prematurely over the I-5 Freeway causing a piece of metal shrapnel to strike and damage a CHP patrol vehicle, the agency announced Sunday.

The live ammunition training exercise Saturday was part of the Marine Corps 250th anniversary celebration at Camp Pendleton, which was attended by both Vice President JD Vance and Defense Secretary Pete Hegseth.

CHP says that the incident occurred at 1:46 p.m. while officers were supporting a traffic break along the I-5. The image shared by CHP shows that the shrapnel struck the patrol vehicle on the I-5 near the Las Pulgas Road intersection.

The CHP vehicle struck by the shrapnel was part of Vice President Vance’s protective detail, according to the agency.

“We are aware of the report of a possible airborne detonation of a 155mm artillery round outside the designated impact area during the U.S. Marine Corps Amphibious Capabilities Demonstration at Camp Pendleton, CA, Oct. 18,” wrote the U.S. Marine Corps in a statement to NBC4.

Map shared by the California Highway Patrol showing where the live ammunition was fired on Saturday afternoon, and where it struck and injured a CHP patrol car on the I-5 near Las Pulgas Road. Courtesy of CHP.

No injuries were reported, according to CHP. The agency says that the Marine Corps was immediately notified and that no additional live ordnance was fired over the freeway following the incident.

In their communication, CHP said that an internal report has been filed with the “recommendation to conduct an additional after-action review into the planning, communication, and coordination between federal, state, and local government around the event on Saturday, October 18, to strengthen protocols for future demonstrations and training events near public roadways.” 

The I-5 was closed to the public by CHP in an early morning decision on Saturday from 11 a.m. to 3 p.m. during the live ammunition training exercise.

In response to Sunday’s news, Governor Gavin Newsom who on Saturday criticized the live ammunition training exercise over the I-5 Freeway as a public safety risk, shared the following statement on X: “We love our Marines and owe a debt of gratitude to Camp Pendleton, but next time, the Vice President and the White House shouldn’t be so reckless with people’s lives for their vanity projects.”

We love our Marines and owe a debt of gratitude to Camp Pendleton, but next time, the Vice President and the White House shouldn’t be so reckless with people’s lives for their vanity projects.https://t.co/vQ3epSTvyh

— Governor Gavin Newsom (@CAgovernor) October 19, 2025

The Marine Corps says that an investigation has been initiated to determine the incident’s root cause.