SE : U.S. Coast Guard official says Japanese trawler has sunk . NEW : It is about 100 miles west of Southeast Alaska , an unofficial estimate . Authorities say it is a navigation hazard . The boat is part of a giant debris field making its way toward North America .
NEW : U.S. Coast Guard official says Japanese trawler has capsized . NEW : It sank about 180 miles west of Southeast Alaska , an official says . Authorities say it is a navigation hazard . The boat is part of a giant debris field making its way toward North America .