This image made from Japan's NHK public television via Kyodo News shows the Fukushima Daiichi power plant's Unit 1, left, in Okumamachi, Fukushima prefecture, Japan, Saturday, March 12, 2011. The walls of the building at nuclear power station crumbled Saturday as smoke poured out and Japanese officials said they feared the reactor could melt down following the failure of its cooling system in a powerful earthquake and tsunami. (AP Photo/NHK TV via Kyodo News)