It's fifty years ago today that we learned of the tragedy in the Welsh village of Aberfan. Mark Hutchings reports:
Oct 21, 2016, 06:26 AM
On the 21st of October 1966 a colliery waste tip suffered a catastrophic collapse which killed one hundred and sixteen children and twenty eight adults. It was caused by a build-up of water in the accumulated rock and shale, which suddenly started to slide downhill in the form of slurry.