▶ Watch Video: Families call for change one year after fatal Marine training accident

One year after nine U.S. service members drowned in a training accident, families of the fallen are taking steps to make sure it never happens again. Nearly a dozen Marines, including a general, have been disciplined in the July 30 accident.

Cell phone videos of the Marines crammed into an amphibious assault vehicle only last for seconds. They had no way of knowing that within hours, nine would die — drowned when their vehicle sank off the coast of California.

It’s been a year since the accident, and as seen from press conferences the families held, the grief for the fallen is still raw. One of those who drowned, Lance Corporal Chase Sweetwood, was just 18.

“Why is my son gone? Why was he not kept safe?” said one of his parents.

The Marines had left the mother ship in their tracked vehicle for a practice landing on San Clemente Island. Private First Class Bryan Baltierra texted his father, “our track started smoking.”

Bryan joined the Marines at the age of 17, and was killed on his one-year anniversary of joining.

“It was the transmission,” Carlos, Bryan’s father, said. “Due to no transmission fluid in the vehicle.”

The transmission failed, the engine quit and the vehicle started taking on water. It took 45 minutes for help to arrive.

“One of the boys who did survive did say ‘when I looked back … I saw Bryan and his roommate Evan Bath at a bench, praying,'” Carlos said.

The grief-stricken families called on the Marine Corps not to allow any amphibious assault vehicles back in the water until their flaws are fixed. They also filed a lawsuit Thursday against BAE Systems, the vehicle manufacturer.

The lawsuit is meant to force the manufacturer to fix defects in the vehicles that led to them sinking as well as a defect that prevented the service members from getting out of the vehicle as it sank, according to lawyers representing the families who were contacted by CBS San Diego.

The lawsuit alleges BAE Systems knew for years about a defective cargo hatch door and never corrected it, CBS San Diego reported.

“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 to the station.