The Wikipedia article of the day for October 21, 2018 is Aberfan disaster.
The Aberfan disaster was the catastrophic collapse of a coal-mining spoil tip that caused the deaths of 116 children and 28 adults on 21 October 1966. The tip had been created on a mountain slope above the Welsh village of Aberfan, near Merthyr Tydfil, and overlaid a natural spring. Heavy rain led to a build-up of water within the tip which caused it to suddenly slide downhill as a slurry, engulfing the local junior school and other buildings. There were seven spoil tips on the slopes above Aberfan; the one that slipped onto the village was 111 feet (34 m) high. The tip was the responsibility of the National Coal Board (NCB), and the subsequent inquiry placed the blame for the disaster on the organisation and nine named employees. The organisation’s chairman, Lord Robens, was criticised for making misleading statements. Neither the NCB nor any of its employees were prosecuted and the organisation was not fined. Half of the village’s surviving children suffered post-traumatic stress disorder.