Report: Human, mechanical errors caused tank to sink

SAN DIEGO — Inadequate training, shabby maintenance and poor judgment by leaders led to the sinking of a seafaring tank last year off Southern California that killed nine service members, according to findings of a Marine Corps investigation released Thursday.

The report detailed a slew of missteps and oversights that left the crew of the amphibious assault vehicle in the dark trying to find an unmarked escape hatch as they took on water.

“Ultimately this tragic mishap was preventable,” wrote Lt. Gen. Steven R. Rudder, commander of U.S. Marine Corps Forces, Pacific, in his review of the investigation.

It was one of the deadliest Marine training accidents in decades. Three commanders have been dismissed as a result, including the leader of the 15th Marine Expeditionary Unit who oversaw the training exercise in the summer of 2020 off San Clemente Island, about 70 miles northwest of San Diego.

Seven other military personnel faced administrative or disciplinary action.

The training exercise was fraught even before it began. The investigation found inadequate training of the platoon members who were provided 14 amphibious assault vehicles that had not been used in more than a year and were in “poor condition.” The platoon made repairs in a rush to meet a deadline, according to the investigation.

During the training exercise the vehicles were headed to a Navy ship after leaving the shores of San Clemente Island on July 30. One of the tanks with three crew members, 12 Marines and one sailor started taking in water shortly after 6 p.m.

A crew member alerted the vehicle commander who only responded “thanks, for letting me know,” according to the investigation. The troops should have immediately been ordered to remove their gear and prepare to evacuate, according to military safety procedures.

The tank suffered numerous leaks, one of which was from a poorly installed headlight that left a gap in the hull area. There also was no oil in the transmission, according to the findings. The generator went out, and the pump needed to flush out the water started failing.

The emergency lights did not function, and no markings were put on a side hatch, leaving troops scrambling in the dark, using their cell phone lights to find it, according to the findings.

Once they did, they struggled to open it. As they finally pried open the hatch, another assault vehicle came to rescue the crew and ended up colliding with the distressed vessel, which turned broadside into a wave that swept over it.

The troops were knocked off their feet and water flooded through the hatch, causing the vehicle to rapidly sink. Seven Marines and one Navy corpsman went down with the tank. An eighth Marine who was among those rescued later died.