An earthquake of the magnitude of 6.8 on the Richter scale struck Japan on 16 July 2007 killing seven people in the city of Kashiwazaki and damaging a large nuclear reactor. The damage to the reactor, one of the largest in the world, caused a leak that released a small amount of water containing radioactive materials into the sea. The quake also left hundreds injured and caused widespread devastation in Niigata Prefecture.