what was unpredictable and outside our imagination

記憶がどこかに行ってしまわないことを願いつつ、言葉を拾います。「想定外」には種々の英訳がありますが、outside our imaginationは同じように震災を経験したNZの新聞の記事からのものです。（UG）

The Japanese government has pledged to reduce reliance on nuclear power, which supplied about 30 percent of the nation's energy needs before the disaster, but says it needs to restart some nuclear plants to meet Japan's energy needs during the transition period.

Japan's prime minister has acknowledged failures in the government's response to the disaster, being too slow in relaying key information and believing too much in "a myth of safety" about nuclear power.

"We can no longer make the excuse that what was unpredictable and outside our imagination has happened," Prime Minister Yoshihiko Noda told a group of reporters last weekend. "Crisis management requires us to imagine what may be outside our imagination."

The phrase "soteigai," or "outside our imagination," was used repeatedly by Tokyo Electric Power Co, the utility that runs the Fukushima plant, as the reason it was not prepared for the giant tsunami. Although some scholars had warned about such tsunami risks, both the utility and regulators did little to prepare for such an event, and kept backup generators in basements, where they could be flooded.

"We can say in hindsight that the government, business and scholars had all been seeped in a myth of safety," Noda said of the oversights in the accident. "The responsibility must be shared."

http://www.stuff.co.nz/waikato-times/news/world-news/6556398/Japan-mourns-tsunami-dead