Osarizawa mine tailings dam collapse incident

...After that, it developed as a central mine for the Mitsubishi zaibatsu, and was the fifth largest copper producer after Ashio, Besshi, Kosaka, and Hitachi. In November 1936, during the quasi-wartime regime, a huge 60m-high tailings dam collapsed due to increased production without regard for safety, causing a major disaster with 362 deaths and 400 collapsed houses, and it collapsed again in December of the same year (Osarizawa Mine Tailings Dam Collapse Incident). At its peak after World War II, around 1958, it produced 7,000 tons of copper, but in the 1960s, the mining situation worsened, and smelting was discontinued in March 1966. In April 1972, it was spun off as a wholly owned subsidiary of Mitsubishi Metal Mining (now Mitsubishi Materials) and became Osarizawa Mining Co., Ltd., but closed in May 1978. ...

*Some of the terminology used in reference to the "Osarizawa Mine Tailings Dam Collapse Incident" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…以後，三菱財閥の中心的鉱山として発展し，足尾，別子，小坂，日立に次いで産銅第5位を誇った。準戦時体制下の1936年11月安全性を無視した増産が原因で高さ60mの巨大な鉱滓ダムが決壊し，死者362人，家屋倒壊400棟の大惨事を引き起こし，同年12月にも再び決壊した(尾去沢鉱山鉱滓ダム決壊事件)。第2次大戦後最盛期の58年ころには7000tの銅を生産したが，60年代になって鉱況が悪化し，66年3月製錬中止，72年4月三菱金属鉱業(現，三菱マテリアル)の全額出資子会社として分離独立し，尾去沢鉱山株式会社となるが，78年5月閉山した。…

※「尾去沢鉱山鉱滓ダム決壊事件」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報