Fukushima Dai-ichi ("dai-ichi" means "#1"), is a multi-reactor nuclear power site in the Fukushima Prefecture of Japan. The Fukushima Daiichi nuclear disaster occurred after a 9.0 magnitude Tōhoku earthquake and subsequent tsunami on 11 March 2011. This offshore earthquake, near the island of Honshu, produced a large tsunami in Japan, and a tsunami warning for over 20 countries within and around the Pacific Rim.