Aberfan Disaster

The Aberfan disaster was the catastrophic collapse of a colliery spoil tip 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, killing 116 children and 28 adults as it engulfed Pantglas Junior School and a row of houses. The tip was the responsibility of the National Coal Board, and the subsequent inquiry placed the blame for the disaster on the organisation and nine named employees. There were seven spoil tips on the hills above Aberfan; Tip 7—the one that slipped onto the village—was started in 1958 and, at the time of the disaster, was 111 feet high. In contravention of the NCB's procedures, the tip was partly based on ground from which springs emerged.

Data Source : Wikipedia