The Marine Corps announced on Friday the identity of the Marine who tragically lost his life in a training accident in Southern California on Wednesday. He was 21-year-old Tanner F. Rubio.

Rubio, who held the rank of private first class, died in what officials described as a “tactical vehicle mishap” that occurred in the afternoon at Camp Pendleton, located in San Diego County. He was part of the I Marine Expeditionary Force (I MEF), the largest Marine Air-Ground Task Force (MAGTF) within the Corps.

Originally from Dixon, California, Rubio enlisted in the Marine Corps in January 2025. He underwent training as an infantry rifleman to prepare for frontline combat and served in a battalion of the 1st Marine Regiment, under the 1st Marine Division, a key combat unit of the Marine Corps.

Expressing his condolences, Maj. Gen. Thomas Savage, commanding general of the 1st Marine Division, stated, “The tragic loss of Pfc. Rubio is one felt across the 1st Marine Division. He will be sorely missed, but his honorable service to his country will not be forgotten. All of us at the Blue Diamond will keep him and his family in our thoughts and prayers.”

Tanner F. Rubio was identified as the Marine who died during a training accident on December 3, 2025. (U.S. Marine Corps)

His death was not related to Steel Knight, an annual training exercise that began Monday on the base, officials said. 

State Sen. Catherine Blakespear, whose district includes Camp Pendleton, previously described the accident as “tremendously upsetting” and emphasized the sacrifices Marines make to protect the nation.

A view of U.S. Marines training on Amphibious Combat Vehicles (ACV) at Camp Pendleton Friday, Sept. 26, 2025. (Allen J. Schaben/Los Angeles Times)

“I am incredibly saddened to learn of the tragic training accident at Camp Pendleton that claimed the life of a Marine from the 1st Marine Expeditionary Force,” Blakespear said in a Facebook post Wednesday. “My heart and deepest sympathies go out to the Marine’s family, loved ones, and other service members who are grieving this loss.

A view of the sign at Marine Corps Base Camp Pendleton Friday, Sept. 26, 2025. (Allen J. Schaben/Los Angeles Times)

“Our Marines put themselves in harm’s way every day even on home soil during routine training so that our nation remains safe. Representing Camp Pendleton and these service members is a true honor and hearing of this is tremendously upsetting.”

“I will be closely monitoring the investigation into this accident. In this difficult moment, I extend my condolences to all who are mourning within the Camp Pendleton community.”

Fox News Digital reached out to the I Marine Expeditionary Force for more information.