The waste tip had been piled on a hillside over a spring, and heavy rain turned part of it into a slurry that slid down at about 9:15 a.m., minutes after pupils had arrived for the last day before half-term. Miners and villagers dug through the rubble with their hands, but no one was rescued alive after 11 a.m. A tribunal blamed the National Coal Board, whose chairman, Lord Robens, had been slow to accept responsibility. No one was prosecuted, and the Board was never fined.
Aberfan lay below a series of waste tips from the Merthyr Vale colliery. Tip No. 7, begun in 1958, had been built over natural springs, and local officials had raised concerns about the tips for years. After weeks of heavy rain, the top of the tip sank in the early morning of October 21, 1966, and at about 9:15 a.m. some 110,000 cubic meters of waste broke away and flowed down the mountain.
It crossed a canal and a railway embankment and engulfed Pantglas Junior School and about 20 houses. Fog hid the tip from those below, and many heard only a roar. Children had just left morning assembly, where they had sung "All Things Bright and Beautiful". Most of those who died were between seven and ten years old.
The tribunal's report in 1967 found that the disaster could and should have been prevented. The Coal Board's chairman had first claimed the springs were unknown. A disaster fund raised from public donations was forced to pay £150,000 toward removing the remaining tips, a sum the government repaid in 1997. Queen Elizabeth II, who visited eight days later, later said her delay was one of her greatest regrets.
Key people: Lord Robens, Queen Elizabeth II