At least two others were injured in the accident, which occurred Thursday, according to a tweet from the 1st Marine Expeditionary Force.
Search and rescue efforts are still underway Friday morning with support from the Navy and Coast Guard.
All of the service members in the incident are assigned to the 15th Marine Expeditionary Unit, based out of Camp Pendleton.
“We are deeply saddened by this tragic incident,” said
Col. Christopher Bronzi, the commanding officer of the 15th MEU. “I ask that you keep our Marines, Sailors, and their families in your prayers as we continue our search.”
This is a breaking story and will be updated.