Survivor John Lawler said the fishing boat listed hard to the starboard side and although no emergency alarms sounded, he was convinced the vessel was in grave danger.
The Coast Guard, FBI and U.S. attorney's office in Los Angeles are leading a criminal probe, and the National Transportation Safety Board is investigating safety issues.
Federal investigators also identified a violation of Coast Guard regulations that could trigger criminal charges in the California dive boat disaster that killed 34 people.
More than half the 34 people killed as they slept in bunks below deck early Monday have been positively identified through DNA, and their family members around the world are being notified.
