It was reported that the ship could have sank. The crew prevented it. One thing they must have done was seal off the compartments open to the sea by locking the watertight doors.
The sailors killed were in their bunks- which would have been on a lower level in the ship.
Which makes me wonder if they weren't drowned when the compartment doors were sealed.
By the way, that ship, a mere destroyer, cost a pretty penny. $1.5 billion, or 1,500 millions of dollars. The ship has very advanced navigation and warning equipment, so it's a mystery so far as to how the accident could have happened.