51963 Mitsui Miike coalmine accident (Japan, 458 casualties)
A poster showing the coal dust explosion at the Mitsui Miike mine
Mitsui Miike coalmine experiences a rattling explosion about 500-meters beneath the surface. The explosion ended up collapsing the tunnel roofs at various locations. The majority of the Mitsui Miike Coalmine deaths were the result of carbon monoxide poisoning. Regardless of their cause of death, 458 miners lost their lives while on the job. The coalmine continued operating until 1997.