In a significant disruption, a 17-mile portion of the I-5 freeway in Southern California was closed on Saturday. This closure was due to a live ammunition demonstration commemorating the 250th anniversary of the U.S. Marine Corps at Camp Pendleton.

The California Highway Patrol (CHP) announced that both directions of the freeway, from Harbor Drive in Oceanside to Basilone Road near San Onofre, were affected. The closure commenced at 11 a.m., quickly leading to a buildup of heavy traffic as motorists navigated the detours.

The CHP clarified in a statement that this military event would feature “live ammunition being discharged by the federal government over the freeway,” underscoring the need for heightened safety precautions during the anniversary celebrations.

The transportation challenges extended beyond the freeway, as there was no Amtrak service available between Orange and San Diego counties while the I-5 remained closed. Commuters were advised to plan alternate routes to accommodate the closure.

Footage released by California officials highlighted the intensity of the operation, showing live munitions being fired in what appeared to be a practice run on Friday, setting the stage for Saturday’s demonstration.

The decision to fire live ammunition during the event sparked significant public outcry. Concerns were further amplified when the Trump administration announced the Marine Corps’ plans, which included the possibility of shutting down this crucial stretch of the freeway adjacent to the base.

On Thursday, the Marines said the celebration would not shut down the freeway.

But the state was asked Friday to put signage along the freeway that read “Overhead fire in progress,” according to a statement from Gov. Gavin Newsom’s office. Early Saturday morning, the federal government informed the state that the live fire activities were scheduled for Saturday afternoon.

Due to the safety risk and distractions to drivers, the CHP made the call to temporarily shut down the freeway.

Over 80,000 travelers and $94 million in freight travel the freeway every day, according to Newsom’s office.

The Marine Corps is celebrating its 250th anniversary on Saturday afternoon at Camp Pendleton. The vice president, war secretary and thousands of other spectators are expected to attend the live-fire exercise.

The actual birthday of the Marine Corps is Nov. 10.