Mothers waved off their children in the small mining village of Aberfan, for the last day of school before the half term break, it was 21st October 1966. Up on the hillside, overshadowing the village were several large coal slurry tips, hundreds of feet high, waste from the mines that dotted around the village. Children now grown recall playing in the stream of water that fed out from springs underneath, and increased with the usual rainfall of the area. At around 7.30 that morning as the team that controlled the waste tips reached the top of the tips, they noticed a depression had occurred, and that the waste hill seemed…