Deadly AAV mishap off San Clemente Island attributed to 'human and mechanical failures'

Marines, JGSDF conduct amphibious landing on Pendleton
Posted at 7:27 AM, Mar 26, 2021
and last updated 2021-03-26 14:47:15-04

SAN DIEGO (KGTV) — A "confluence of human and mechanical failures," including a tragic collision mid-rescue, are being blamed for the deadly AAV accident off San Clemente Island last July.

That combination of failures contributed to not only the July 30 training accident but to a "delayed rescue effort," according to a report of the Marine Corps' command investigation.

Specifically, the report states that mechanical failures and a disregard of maintenance procedures, AAV crewmen not evacuating personnel when needed, and improper training on AAV safety procedures played a factor.

On July 30, the report states that 13 amphibious assault vehicles from the USS Somerset were on San Clemente Island, but due to a mechanical failure of one AAV, some personnel and AAVs remained on the island. Only nine of the 13 AAVs initially departed to return to the USS Somerset.


During that return, one of the AAVs began to take on water through"multiple points of leakage," the report stated. The AAV's "transmission failed, bilge pumps were unable to expel water rapidly enough due to the transmission failure, and the AAV began to sink. The vehicle commander gave the distress signal, known as a 'November flag,' but no safety boats were in the water, and it took approximately 20 minutes for another AAV to arrive to assist," the report adds.

That AAV, with 11 service members inside, slowly sank for about 45 minutes before another AAV arrived to help, according to the report. Though when that second vehicle arrived, disaster struck.

"The mishap AAV crew prepared to evacuate embarked personnel by opening a hatch on the top of the vehicle. The AAVs collided, causing the mishap AAV to turn broadside to a swell. A large wave swept over the mishap AAV, in which water entered the troop compartment through the open hatch, and caused the mishap AAV to rapidly sink with eleven personnel on board," the report said.


The training mishap killed Pfc. Bryan J. Baltierra, 19, of Corona, California, a rifleman with Bravo Company; Lance Cpl. Marco A. Barranco, 21, of Montebello, California, a rifleman with Bravo Company; Pfc. Evan A. Bath, 19, of Oak Creek, Wisconsin, a rifleman with Bravo Company; U.S. Navy Hospitalman Christopher Gnem, 22, of Stockton, California, a hospital corpsman with Bravo Company; Pfc. Jack Ryan Ostrovsky, 21, of Bend, Oregon, a rifleman with Bravo Company; Cpl. Wesley A. Rodd, 23, of Harris, Texas, a rifleman with Bravo Company; Lance Cpl. Chase D. Sweetwood, 19, of Portland, Oregon, a rifleman with Bravo Company; and Cpl. Cesar A. Villanueva, 21, of Riverside, California, a rifleman with Bravo Company.

Following the deadly incident, the Marine Corps order all AAV water-based operations to be suspended, pending a review of equipment, procedures, and training. All AAV units were ordered to conduct additional inspections of every vehicle with new criteria as well, the report said.

Several other safety policies and procedures have been instituted in regard to AAV units.

Following the investigation, the Marine Corps relieved Colonel Christopher J. Bronzi, commanding officer of the 15th Marine Expeditionary Unit, from his role. In October, Lt. Col. Michael J. Regner, commanding officer of Battalion Landing Team, 1st Battalion, 4th Marines, was removed.

The Marine Corps said that seven other personnel "whose failures contributed to the mishap" have also been disciplined.