One Marine died, two service members were injured and eight others were missing and later presumed dead after an accident involving an amphibious assault vehicle off the coast of Southern California on Thursday, the authorities said.
Search and rescue efforts to find the missing people — seven marines and one sailor who were aboard the vehicle when it sank — were called off on Saturday evening, the First Marine Expeditionary Force said, with the service members now presumed dead. They were assigned to the 15th Marine Expeditionary Unit at Camp Pendleton, in the San Diego area. Efforts were now turning to recovering their remains, the First Marine Expeditionary Force said.
The Marine who died, whose name was not released, was pronounced dead at the Scripps Memorial Hospital La Jolla, a news release from the Marine unit said. Both of the injured Marines were in stable condition, Lt. Gen. Joseph L. Osterman, commanding general of the I Marine Expeditionary Force, said at a news conference on Friday afternoon.
There had been 15 Marines and one sailor inside the amphibious vehicle, the force said. According to the news release, Marines aboard the vehicle reported taking on water around 5:45 p.m. on Thursday.
At the time of the accident the vehicle was traveling from San Clemente Island back to a ship that was more than 1,000 meters off shore, Gen. David H. Berger, Commandant of the Marine Corps, said at the news conference.
Two nearby amphibious assault vehicles witnessed it sink and were able to pinpoint its exact location, General Berger said.
“The adjacent A.A.V.’s watched it go down, and at 26 tons, the assumption is that it went down to the bottom,” Lt. Gen. Osterman said.
Officials said it was unclear how the accident happened. The Navy and the Coast Guard had been assisting in the search for the missing service members, the force said, and A.A.V. water operations have been suspended while the Marine Corps investigates the accident.
The depth of the water drops off quickly around the island, so the vehicle was in several hundred feet of water when it sank, Lt. Gen. Osterman said. When the vehicle left shore, conditions had been acceptable for travel, he said.
Lt. Gen. Osterman estimated that the oldest person aboard the vehicle was around mid-30s and the youngest was around 18. Those on board were wearing combat gear and flotation devices, he said.
There are around 800 amphibious assault vehicles in Marine inventory, he said, each of which can carry up to 21 people and weigh 26 tons.
A.A.V.’s are slow, lightly armored and are considered by many Marines as particularly vulnerable, especially during conflict. As the Marines have sought a replacement, the A.A.V. has remained a cornerstone in the Corps’ inventory, simply because of its amphibious capabilities. It is prone to leaking while at sea from both its rear ramp and troop compartment.
“It is with a heavy heart that I decided to conclude the search and rescue effort,” Col. Christopher Bronzi, a commanding officer, said in a statement on Saturday. “The steadfast dedication of the Marines, sailors and Coast Guardsmen to the persistent rescue effort was tremendous.”
Camp Pendleton hosts the largest Marine base on the West Coast, and Marines often practice beach assaults there using the amphibious troop transport vehicles.
Marines have used the vehicles to move troops from the sea and land since the 1970s. In 2017, 15 Marines were wounded when an amphibious vehicle they were training in caught fire at Camp Pendleton.
Thomas Gibbons-Neff contributed reporting.