SAN DIEGO — A Navy sailor was killed and five others were hurt when a military convoy was involved in a chain reaction crash Tuesday morning, according to authorities.

California Highway Patrol said five military trucks were southbound on Interstate 5 near San Onofre State Beach just before 7 a.m.

“For reasons that are still under investigation, the convoy began to slow causing a chain reaction collision. One of the truck trailers was pushed forward into the cab causing fatal injuries to the driver,” CHP said in a news release.

A 26-year-old service member died at the scene. Another sailor in his early 20s has severe injuries and four other service members, two women and two men in their early 20s, suffered minor injuries, CHP said.

The surviving victims were taken to Camp Pendleton Naval Hospital and Mission Hospital in Orange County for treatment.

First responders and personnel from CHP’s Oceanside area, Camp Pendleton Fire Department, United States Marine Corps Camp Pendleton Provost Marshal’s Office and the United States Marine Corps Criminal Investigation Division responded to the scene.

The Naval Mobile Construction Battalion 5 released a statement Tuesday afternoon about the crash.

“We mourn the loss of our shipmate, our thoughts and prayers are with the sailor’s family, friends, and coworkers during this difficult time. NMCB-5 is supporting all the service members’ family, friends, and loved ones during this time of grief,” the statement said.

Grief counseling and support services will be available through the Navy. Out of respect for the privacy of families, the identity of the sailor killed will be withheld for 24 hours after next of kin notification, the statement said.

The crash is under investigation and CHP is asking anyone with information to contact their Oceanside office at 760-643-3400.