The U.S. nuclear-powered submarine La Jolla caught fire early Wednesday at a naval base in Sasebo, Nagasaki Prefecture, but the blaze was soon extinguished by crew members without any injuries reported, local firefighters said.

The U.S. side reported the incident to the Sasebo municipal government around 11:40 am, and Mayor Akira Mitsutake called for an investigation into the cause and measures to prevent a recurrence.

http://japantoday.com/e/?content=news&cat=1&id=306935

This was incredibly dangerous. Had this submarine exploded god knows how many japanese people would have been injured. Not to mention the damage to the enviornment. Luckily no japanese citizens were actually harmed here.