The Aberfan disaster buried a Welsh village school

On the morning of 21 October 1966, a vast spoil tip of coal-mining waste perched above the South Wales village of Aberfan began to move. Saturated by days of rain and built over hidden springs, the tip liquefied into a fast-moving black slurry that surged down the mountainside toward the homes and school below.

The slide engulfed Pantglas Junior School and a row of houses just as lessons were beginning on the final day before half-term. In total, 144 people died, 116 of them children, most aged between seven and ten. It remains the worst mining-related disaster in British history.

Blame for the disaster rested squarely on the National Coal Board, whose tips overlay known streams and ignored years of warnings.

Residents had complained for years about tipping above the school, and the Board had been warned of flooding risks. A government tribunal later found the catastrophe was avoidable, reshaping how Britain regulates the stability of industrial waste tips.