The families of 9 US troops who died when their AAV sank have decided to sue the company that made the vehicle

• The families of nine troops who died when their AAV sank last summer are suing BAE Systems.
• Lawyers representing the families argued that known vehicle defects caused their deaths.
• The Marine Corps investigated last summer's AAV accident and placed the blame on other issues.

Lawyers representing the families of nine US service members who died when their assault amphibious vehicle sank last year announced Thursday they are filing a lawsuit against BAE Systems, the vehicle maker.

Last summer, an AAV assigned to Bravo Company, Battalion Landing Team 1st Battalion, 4th Marines, part of the 15th Marine Expeditionary Unit, sank off the coast of California.

The mishap vehicle was carrying three AAV crewmembers, 12 Marine infantrymen, and one Navy corpsman. Eight embarked Marines and the sailor died, making this incident the deadliest AAV training accident in the vehicle's history.

A Marine Corps command investigation into the accident determined that "a confluence of human and mechanical failures," specifically improper maintenance, failure to follow procedure, and insufficient training, caused the vehicle to sink and led to the deaths of nine people.

Speaking at a press event Thursday in Oceanside, California, lawyers representing the families of the deceased argued that these issues, while problematic, are secondary to alleged vehicle defects that made it impossible for all of the service members aboard to egress.

"The truth has not be told to these families," attorney Annee Della Donna said, arguing that "the real reason they died is there was no way for them to get out alive."

Citing discussions with survivors and other witnesses, she said that the troops aboard the AAV struggled to open the hatch for the primary point of egress, identifying this as a critical design flaw that left some service members trapped.

"BAE Systems has known about these defects for decades," the attorney said, accusing the defense firm of taking billions of dollars from US taxpayers to build "death traps," a description that a former Marine who was injured in an AAV used for the vehicles in past discussions with Insider.

"They could not get out," Della Donna said. "They died a horrible death at the bottom of the ocean."

The Marine Corps investigation acknowledged that service members in the AAV struggled with the hatch but did not identify this as a cause of death.

Della Donna's colleague Eric Dubin argued that the "lawsuit is necessary for accountability."

BAE received a contract in 2018 to build the new amphibious combat vehicle to replace the Corps' aging fleet of AAVs. The Corps began introducing the new ACVs last fall.

"We offer our deepest sympathies to the families impacted by this tragedy and we mourn the loss of the nine service members," BAE Systems said in a statement, adding that this company is "not in a position to comment on ongoing litigation."

The attorneys representing the nine families said during the press conference that while the military also deserves to be held accountable, there are legal restrictions in place that prevent them from taking action against the US federal government.

The attorneys said the lawsuit against BAE Systems will be filed within the next 48 hours. This suit is directed solely at BAE Systems; however, Della Donna told Insider that if other firms are found to be responsible, her team will consider additional legal action.