空前絶後

Meanings

1. Noun, No-adjective

   (so marvelous or horrible that it may be) the first and probably the lastFour-character idiom

• 2011年ねん（平成へいせい23年ねん）3月つき11日ひに、福島ふくしまで空前絶後くうぜんぜつごの事故じこが起おきた。

  On the 11th of March 2011, an unprecedented accident took place in Fukushima.