Aberfan totally changed my life. I was a British Coal scientific technician in a lab near Swansea when it happened. We were all horrified, of course, and soon British Coal woke up to its responsibilities and started examining all its tips for stability and dangers. They established a soil mechanics laboratory at its Regional Laboratory in Wath-On-Dearne, South Yorkshire and I got a job in it. I spent several years trudging round tips collecting samples, testing for density and stability and other properties. Tips had a lot more real civil engineering input into their design and construction - spoil was no longer just dumped, and much was removed for use in road construction - there's quite a lot under parts of the M62 for example, and earthworks around the Thames barrier and the old Pegwell Bay hoverport. In one of our experiments I managed to lose a finger tip in my left hand and had to relearn how to play banjo after 10 years playing it normally.
I've been in Yorkshire ever since and made many musical friends, so it's an ill wind that blows nobody any good!