The Coast Guard was initially misinformed about the number of persons on board the vessel, and secured the search with one crew member still unaccounted for.

According to the United States NTSB (National Transportation Safety Board), the triggering event in the sinking was the loss of one of the two rudders.

The NTSB can only speculate that the door was left open, the seals or latching dogs failed, or that the holes cut in the bulkhead for refrigeration lines needed for fish processing were not watertight.

suspect that modifications made to the housing surrounding the propeller failed due to poor installing causing the rapid flooding.

Evidence of the failure is shown through maintenance records indicating multiple repairs on the propeller housing where it joins the hull.

This means the captain can keep the diesel engines at a constant RPM needed for the AC electrical generators, and use the variable pitch to change vessel speed or reverse direction.

The Coast Guard had tested the engine emergency shutoff system a year before the sinking and reported that it functioned properly.

The Marine Board reviewed thousands of pages of documents and photographs related to the maintenance and repair of the vessel, and examined in-depth the installation of the Kort nozzles.

As a result of this analysis the report concluded that "Though the exact initiating event that created the source of flooding is unknown, it was likely related to the poor material condition of the vessel and may have been related to the Kort nozzle struts which are believed to have experienced excessive stresses where they were attached to the hull."

The report added that the owners of the ship "failed to properly maintain the structural condition of the Alaska Ranger".

The unexpected and unexplained flooding of the ship meant that the crew had to abandon the vessel at night, into the frigid waters of the Bering Sea.