“I guess the senior officer on watch that night will have some splainin to do.”
He/she and the Captain will have plenty of opportunity at their Courts Martial...perhaps along with others on watch that night.
First there would be in the Army what is called an Article 32 investigation, a very senior officer and likely former ship captain appointed to investigate. That report would likely go to the PAC COM Commander for his action, appointing a courts martial or whatever his options are. You are right, more than one person is going to be deeply involved here.