The Mitsui Miike Coal Mine disaster was an accidental explosion at the Miike coal mine in Kyushu, Japan on 9 November 1963. 458 people were killed by the explosion or by carbon monoxide poisoning caused by the explosion. 839 others were injured by the blast or carbon monoxide poisoning. Many of the poisoned survivors suffered severe, permanent brain damage.
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Mitsui Miike Coal Mine disaster Wikipedia(Text) CC BY-SA