Emergency crews were still combing through the Sea of Okhotsk on Friday. (Credit: Russian Ministry of Emergency Situations)

Rescuers in Russia are continuing to search for crew members from a sunken factory trawler.

The Dalny Vostok capsized on Wednesday with 132 people on board. So far, 56 have been reported dead and 13 are still missing, according to the Voice of America.

The mostly Russian crew was out fishing for pollock this week in the Sea of Okhotsk off the Kamchatka Peninsula. It’s not clear what caused their 338-foot vessel to flip and sink.

Investigators with Russia’s emergency ministry are looking into claims that the trawler struck ice and starting taking on water near the engine room. But survivors told the Siberian Times that their boat may have been overloaded with fish. 

The Dalny Vostok is the second factory trawler to sink in Russia’s Far East this winter. The Oryong 501, a South Korean ship, was also fishing for pollock when it was swamped by a wave. Out of the 60 people on board, just seven survived.