ANCHORAGE, Alaska (AP) - Federal accident investigators say evidence indicates an ice accumulation likely led to the deadly sinking of a crab boat last year near an Alaska island.

The National Transportation Safety Board issued a marine accident brief and a safety alert Thursday to warn mariners about icing. The action follows the agency's investigation into the Feb. 11, 2017, sinking of the Seattle-based vessel Destination with six people on board.

The NTSB also says the probable cause of the sinking was the boat's captain's decision to proceed in heavy freezing spray conditions without ensuring the vessel was stable enough to withstand ice accumulations.

None of those on board were found and the crew was presumed dead. The 110-foot (34 meters) boat was found months later in waters near St. George Island.

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