Federal investigators interviewed crewmen of the Alaska Ranger, as well as toured its sister ship, the Alaska Warrior Saturday, said the Coast Guard.

The engineer working the overnight watch on the Alaska Ranger told investigators he saw "major flooding" in the ship's rudder room before the Seattle-based fishing boat sank in the Bering Sea.

According to the Coast Guard, the Alaska Ranger's engineer heard a high water alarm, and the alarm panel indicated it was coming from the rudder room. He ran to check the rudder room, opened the watertight door, saw water, closed the door and called the bridge to report major flooding.

He also advised the bridge to sound the general alarm. Other engineers responded, saw water spreading through the vessel, and began shutting off power to keep from being electrocuted, according to the Coast Guard.

First Engineer James Madruga testified Friday that no water had entered the rudder room before the vessel departed Dutch Harbor on Unalaska Island.

Coast Guard commanders also said they've launched a separate investigation into how crew member Byron Carillo apparently fell from the basket of a rescue helicopter.

Carillo was among five crewmembers that died, 42 others were rescued.

The Alaska Warrior's crew brought aboard 22 survivors, and three bodies.

Fisherman Recovers Own Brother From Sinking Ship’s Victims

The Ranger’s chief engineer and captain are among those credited with saving lives by making sure their crew made it into life rafts. Both went down with the ship.

The federal inquiry is expected to last most of next week in Dutch Harbor, before moving to Seattle.