On 21 October 1966, a generation of schoolchildren from the Welsh mining village of Aberfan was wiped out in one of the worst mining disasters in British history, when a slagheap slid down a hill into the valley below.

The residue of years of mining, the heap had slipped down the valley without warning. It hit the village, destroying the school and other buildings in seconds, killing 116 children and 28 adults.

A government inquiry discovered that the heap of lose rock and mining slag had been wetted by a local spring, causing it to slip with tragic consequences, despite thebest efforts of hundreds of frantic rescuers.

Watch original footage from the desperate rescue attempt in this British Pathé video, above.