Coast Guard cannon fire sinks Japanese ghost ship

It sank into waters more than 6,000 feet deep in the Gulf of Alaska, about 180 miles west of the southeast Alaska coast, the Coast Guard said.

The crew pummeled the ghost ship with high explosive ammunition, and the Ryou-Un Maru soon burst into flames, took on water and began listing, officials said.

A huge column of smoke could be seen over the gulf as a Coast Guard C-130 cargo plane, sent to observe the sinking, dropped a buoy to monitor for any possible pollution from the sunken ship.

The Coast Guard warned mariners to stay away, and aviation authorities did the same for pilots.

In about four hours, the ship vanished into the water, said Chief Petty Officer Kip Wadlow in Juneau.

Officials decided to sink the ship rather than risk the chance of it running aground or endangering other vessels in the busy shipping lanes between North America and Asia.

The ship had no lights or communications system, and its tank was able to carry more than 2,000 gallons of diesel fuel. Officials, however, didn't know how much fuel, if any, was aboard.

"It's less risky than it would be running into shore or running into (maritime) traffic," Coast Guard spokesman Paul Webb said.

The National Oceanic and Atmospheric Administration and the Environmental Protection Agency studied the problem and decided it is safer to sink the ship and let the fuel evaporate in the open water.

A light sheen and minimal debris were visible as the vessel sunk, but the sheen is expected to quickly dissipate, the Coast Guard said in a news release.

The ship was at Hokkaido, Japan, and destined for scrapping when a magnitude-9.0 earthquake that struck the country in March 2011 triggered a tsunami.

The waves dislodged the vessel and set it adrift. In total, about 5 million tons of debris was swept out to sea.