Marines Launch New Probe into Fatal AAV Accident as Families Demand Accountability

Marines aboard an amphibious assault vehicle.
Marines aboard an amphibious assault vehicle exit the well deck of the amphibious assault ship USS Bataan (LHD 5 (U.S. Navy/Mass Communication Specialist 1st Class RJ Stratchko)

For the second time in two years, the Marine Corps is reviewing the lead-up to a fatal accident -- a move that could leave more senior leaders facing fallout over a series of failures that led to nine troops losing their lives.

Assistant Commandant Gen. Gary Thomas on April 2 directed Lt. Gen. Carl Mundy III to serve as president of a new investigation into the way the 15th Marine Expeditionary Unit assembled for its fall deployment last year. Eight Marines and a sailor assigned to that unit were killed during a July pre-deployment training exercise when their amphibious assault vehicle sank off California's coast.

The investigation into the fatal accident found that the tragedy was preventable. Mechanical problems, leadership failures and training gaps all played a role.

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Now, a new investigation will probe not only how the California-based 15th MEU came together ahead of its deployment and its units' training and readiness, but also its "higher headquarters oversight."

"The goal," Marine officials said in a statement, "is to ensure the Marine Corps is doing everything possible to prevent this type of mishap from happening again."

When the 15th MEU began to assemble before its fall deployment, the AAVs selected were far from mission-ready, the investigation found, with most being inoperable.

And once the decades-old vehicles were assigned to the MEU, the commander didn't prioritize their maintenance, according to the investigation. The resulting mishap was the deadliest AAV training accident in the Marine Corps’ history.

Two officers were later relieved of command. Lt. Col. Michael J. Regner, commanding officer of Battalion Landing Team, 1st Battalion, 4th Marines, was relieved in October. Col. Christopher Bronzi, the 15th MEU's commanding officer, was relieved last month while the unit was operating in the Middle East.

No one more senior has been reprimanded over the fatal accident. That's despite Lt. Gen. Steven Rudder noting that Maj. Gen. Robert Castellvi, 1st Marine Division's former commanding officer, bore "some responsibility" over the AAV platoon not completing a combat readiness evaluation before the training exercise. Despite that, Rudder decided "not to take administrative or disciplinary action" against Castellvi.

"[Castellvi] is not responsible for any failure that occurred after the MEU composite date, and he was not the on-scene commander during the mishap," Rudder wrote.

Castellvi is now the Marine Corps' inspector general, overseeing inquiries and investigations.

The investigation also recommended "appropriate administrative or disciplinary action" against the AAV platoon commander, AAV platoon sergeant and vehicle commander. Marine officials have not responded to questions about what actions were taken and when.

Families of some of the Marines killed in the accident say the two reliefs and recommended actions don't go far enough. Christiana Sweetwood said she was devastated by the chain of failures that led to the death of her 18-year-old son Chase.

"It goes clear back to March when they were choosing these AAVs that they knew they didn't have time to fix, that they knew that had major issues," she said. "... Everybody just passed the buck clear to the very, very top. And because of that, our boys are dead."

Anyone who failed the fallen Marines and sailor at any point in that long string of breakdowns must be held accountable, Sweetwood added.

Also killed in the AAV accident were:

  • Cpls. Wesley Rodd and Cesar Villanueva;
  • Lance Cpls. Marco Barranco and Guillermo Perez;
  • Pfcs. Bryan Baltierra, Evan Bath, and Jack Ryan Ostrovsky;
  • Navy Hospitalman Christopher Gnem.

They were assigned to Bravo Company, Battalion Landing Team, 1st Battalion, 4th Marines. Seven other Marines in the vehicle survived.

Aleta Bath, who lost her 19-year-old son Evan, said she worries people who've made mistakes that cost others their lives aren't being held accountable. That, she said, could put more Marines in dangerous situations.

"They may be sent to another command somewhere else -- it doesn't mean that your career is over," Bath said. "And this wasn't where someone made a mistake and missed one call. This was a series of bad judgment calls from start to finish."

The Marine Corps has not responded to questions about whether Castellvi's assignment as the service's inspector general is under review. Castellvi did not respond to a request for comment about the investigation.

Lawmakers are also pressing for action. Rep. John Garamendi, a California Democrat and chair of the House Armed Services subcommittee on readiness, told Task & Purpose that the Marine Corps lacks a culture of safety. Garamendi has been pushing for accountability on a series of fatal military ground vehicle accidents.

"The solution is to fire the generals," Garamendi told Task & Purpose.

This is the second time Thomas, the Marine Corps' second highest-ranking general, has called for another look at a deadly training accident. In 2019, he directed a review into the full investigation into a midair collision off the coast of Japan that killed six.

That review found faults with the previous investigation. Two senior officers who previously went unpunished -- a two-star general and a colonel -- later received formal reprimands over the renewed examination of shortfalls leading up to the crash.

Michael McDowell, the father of 1st Lt. H. Conor McDowell, who was killed in a 2019 vehicle rollover, said the need to perform a second investigation into a deadly mishap points to a cultural problem. In a recent opinion piece for, McDowell called for higher-ranking officers to be held accountable for training accidents.

"After nine young men ... died horrific drowning deaths in an eminently preventable training tragedy last summer, are general officers never to be held accountable, never to be held responsible, never to be penalized?" he wrote. "It certainly looks like it."

Castellvi, he noted, was the general responsible for both his son's unit, 1st Light Armored Reconnaissance Battalion, and the AAV battalion involved in July's accident.

Marine officials did not say when the new probe into the 15th MEU's makeup is expected to be completed. The 15th MEU is wrapping up a deployment to the Middle East and is headed back to California.

-- Gina Harkins can be reached at Follow her on Twitter @ginaaharkins.

Related: 'Tragic Mishap Was Preventable': How the Marines Failed 9 Troops Whose 35-Year-Old AAV Sank in the Pacific

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