The Marine Corps says that its AAVs can hold roughly two dozen troops, but they look like they could only reasonably hold about half that. The vehicle that sank in July was pretty packed, carrying 16 service members at the time of the accident.
Eight Marines and a Navy sailor died. Most appear to have never made it out of the drowning vehicle. The incident was the deadliest training accident in the history of the Corps' amphibious assault vehicles.
The tragedy shook the Corp's confidence in its AAVs, with the commandant suspending waterborne operations pending the outcome of an ongoing investigation. The Corps also fired the commander of the unit involved in the accident.
Amphibious assault vehicle.
What exactly happened to the AAV that sank this summer is still unclear, but what is clear is that a sinking AAV is dangerous, and in some cases, deadly.