Photos and some video are showing up from the U.S. Coast Guard's mission Thursday to sink a a 164-foot "ghost ship" that was set adrift by the March 2011 tsunami that hit northeast Japan.

The Ryou-Un Maru, a fishing vessel, had made its way into the Gulf of Alaska, where it threatened ships traveling through that busy area. It was about 180 miles west of Alaska's southeast coast. Thursday, cannon fire from a U.S. Coast Guard cutter set the ship afire. After about four hours, the ship sank into waters about 6,000 feet deep, Chief Petty Officer Kip Wadlow told The Associated Press.

According to Reuters, "the ship's Japanese owner has said it had no plans to salvage the vessel, and Wadlow said it had been slated to be scrapped even before it was swept away by the tsunami."

Copyright 2016 NPR. To see more, visit http://www.npr.org/.