The collision between a U.S. nuclear-powered submarine and a Japanese fisheries training ship Friday off Oahu Island, Hawaii, was simply unbelievable. It is a sad fact, however, that the collision, which is believed to have been caused by negligence on the part of the submarine, sank the ship, leaving nine students and instructors missing and injuring a dozen others.

The ill-fated ship, the 499-ton Ehime Maru from Uwajima Fisheries High School in Ehime Prefecture, had 35 students and crew members on board when the 6,080-ton USS Greenville smashed into it. The tuna-catching exercise off Hawaii was a traditional program that had continued for more than two decades. For most of the students, it was their first training voyage abroad.

The governments of the two nations take the accident seriously, of course. The Japanese government set up an emergency liaison office at the Cabinet's crisis-management center and sent the parliamentary secretary for foreign affairs to Hawaii. U.S. President George W. Bush immediately issued instructions to the National Security Council and on Tuesday night he apologized for the accident in a direct telephone call to Prime Minister Yoshiro Mori.