Authorities say the man drove towards the base at around noon on Friday, and attempted to get in via Gate 5 before he was shot.
According to the MCRD, the man got out of his vehicle and started walking towards the checkpoint with a knife, apparently ignogring warnings from guards.
He was described as having “hostile intent”, a base spokesperson told The Independent, and was fatally injured by a guard who opened fire.
First responders arrived not longer after to confirm the death of the man, who has not been identified.
The MCRD base is situated on Washington Street and Pacific Highway in San Diego, and adjacent to San Diego’s international airport.
It is the first training stop for recruits entering the US Marine Corps on the West Coast, and in 2021 celebrated its 100 year anniversary.
An investigation is ongoing.
“Out of respect for the ongoing investigative process, at this time we are not able to provide additional details,” the Naval Criminal Investigative Service, who are conducting the investigation, said.