Aberfan: The Disaster They Were Warned About

The danger above Aberfan had been mapped and warnings had been raised. On 21 October 1966, Tip No. 7 flowed into the village, killing 144 people, including 116 children. We explain the water and broken rock behind the failure, what the Tribunal found, and why coal-tip safety still matters. Watch next: The Fire Deadlier Than Chicago Happened the Same Night    • The Fire Deadlier Than Chicago Happened th...   We have deliberately not shown the disaster itself or any victims. Diagrams are simplified schematics. Chapters 0:00 A map, a hillside, a morning 0:58 How does a heap of rock flow? 1:42 Grains, friction and water 2:26 Tip No. 7 and the springs 3:18 From slip to flowslide 4:20 "Impossible to know"? 4:56 The warnings 5:33 What the Tribunal found 6:35 Wales's 2,500 tips today 7:24 A new law and a wetter climate 7:56 Back to the map Sources Report of the Tribunal appointed to inquire into the Disaster at Aberfan on October 21st, 1966 (HMSO, 1967), text via the Durham Mining Museum (archived): http://web.archive.org/web/2020/http:... (paragraph numbers cited on screen). Open Government Licence per the host. Welsh Government, Coal tip safety: https://www.gov.wales/coal-tip-safety Welsh Government, Find disused coal tips: FAQs: https://www.gov.wales/find-disused-co... Welsh Government, Disused Mine and Quarry Tips (Wales) Act 2025: https://www.gov.wales/disused-mine-an... ; legislation text: https://www.legislation.gov.uk/asc/20... Welsh Government, Wales to mark 60th anniversary of the Aberfan disaster: https://www.gov.wales/wales-to-mark-6... British Geological Survey, Aberfan 1966 landslide case study: https://www.bgs.ac.uk/case-studies/ab... UK Parliament (Hansard), Aberfan Disaster debate, 26 Oct 1967: https://api.parliament.uk/historic-ha... BBC News, Tylorstown coal tip slip: https://www.bbc.co.uk/news/uk-wales-5... History & Policy, "Aberfan: no end of a lesson": https://historyandpolicy.org/policy-p... The British Academy Review, Lessons of the Aberfan disaster and its aftermath: https://www.thebritishacademy.ac.uk/p... New Civil Engineer, Aberfan 50 years on: https://www.newcivilengineer.com/late... Photo credits (all changes: resized, cropped to 16:9, slow zoom, text overlays added; no other alterations) "Aberfan Colliery spoil tramway" (July 1964), John Thorn, geograph.org.uk, via Wikimedia Commons: https://commons.wikimedia.org/wiki/Fi... - CC BY-SA 2.0 https://creativecommons.org/licenses/... "Merthyr Vale Aberfan", Darren Wyn Rees / Aberdare Blog, via Wikimedia Commons: https://commons.wikimedia.org/wiki/Fi... - CC BY-SA 4.0 "Coal tip on the mountainside" (2009), Mike Kohnstamm, geograph.org.uk, via Wikimedia Commons: https://commons.wikimedia.org/wiki/Fi... - CC BY-SA 2.0 "Looking down on Aberfan" (2008), Graham Horn, geograph.org.uk, via Wikimedia Commons: https://commons.wikimedia.org/wiki/Fi... - CC BY-SA 2.0 "A view from the farm road above Wattstown looking up to Tylorstown Tip and beyond" (2015), Cwtchman, via Wikimedia Commons: https://commons.wikimedia.org/wiki/Fi... - CC BY-SA 4.0 "Aberfan Memorial Garden, Pantglas" (2015), Angela Llewellyn, via Wikimedia Commons: https://commons.wikimedia.org/wiki/Fi... - CC BY-SA 4.0 Dyffryn Rhondda Colliery, Afan Valley, March 2025: Welsh Government visit announcing coal tip safety funding. Photo: Welsh Government, via Wikimedia Commons: https://commons.wikimedia.org/wiki/Fi... - Open Government Licence v3.0 http://www.nationalarchives.gov.uk/do... Illustrations marked "Illustrative image" are AI-generated (ChatGPT) landscapes and materials; they do not depict Aberfan on 21 October 1966. Maps and cross-sections are our own simplified redraws, not surveys. Narration: AI voice (ElevenLabs). Music: original ambient bed made for this video. Facts checked as of 30 September 2026. Thumbnail: AI-generated illustration. #Aberfan #WelshHistory #EngineeringHistory