I wasn't born until 1968, but I've heard, seen and read a lot about Aberfan over the years and it's heartbreaking.
Not many years ago, a large slap heap in South Yorkshire slipped (ripped up a railway line) - it was found that the thing was unstable as its base was oil drums and they'd rusted away! When we first heard about the heap moving (I work for the train operator whose services were worst affected, so we heard about it when it had only moved a very small amount), then heard the reason why it was moving, my blood ran cold - all I could think about was Aberfan.