Just minutes after the magnitude 9.0 earthquake struck off Japan’s northeast coast on the afternoon of 11 March 2011, waves from the 14-meter tsunami that it triggered crashed over the seawalls built to protect the six reactors at Fukushima Daiichi nuclear plant. Designed to withstand tsunami waves less than half that height, the seawalls were powerless to protect against the flooding that would ensue, cutting off electricity to the plant as power lines were downed by the earthquake and backup generators that had been stored below ground were rendered useless by the flood. Over the next several days, workers scrambled feverishly to cool overheating fuel rods in four of the reactors, then to restore power so that cooling systems could be brought back online, and authorities ordered a precautionary evacuation of those within a 20 km radius of the plant. Despite these efforts to avert a crisis, three of the plant’s reactors experienced partial or full meltdown, rating a Level 7 ‘Major Accident’ on the International Nuclear Events Scale (the most serious category of event, and the second in history) contaminating the site with plutonium and radioactive isotopes and releasing airborne radiation that would reach the United States at measurable levels a week later, and spreading renewed worries about nuclear power further and more quickly.