
The Aberfan disaster was an industrial incident which occurred in the town of Aberfan in southern Wales on the 21st of October 1966. The town had formed one of the major settlements around the Merthyr Vale Colliery since the 1860s. A colliery spoil tip was developed on the hills above the town for waste from the mines as early as the 1910s. The disaster in 1966 occurred as heavy rainwater led to the collapse of the spoil tip. An avalanche of slurry from the tip then came down the hill into the town of Aberfan. The epicenter of the disaster was a local school where five teachers and 109 children lost their lives. Other parts of the town were affected as well. In total 144 people died (128 adults and 16 adults) and much of the town was damaged or destroyed. The disaster began the process of industrial and demographic decline in Aberfan as people moved away from the declining coal-mining town.[1]
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Aberfan disaster chronology of events
The roots of the Aberfan disaster lie nearly a century before the incident itself. Local Welsh people had been extracting coal from the ground here for centuries and in 1869 an English engineer by the name of John Nixon decided to sink a mine in the region to try and extract coal, the fuel of Britain’s Industrial Revolution, at scale. Hence was born the Merthyr Vale colliery. At that time Aberfan was barely even a village. There was just a small collection of cottages here on the side of a hill in the valley. It expanded exponentially, along with several other towns in the vicinity, as the Merthyr Vale colliery became one of the largest in Wales. By the 1960s Aberfan was a thriving town of more than 5,000 people.[2]

Around 1916, as the colliery continued to expand and more and more industrial debris was created, a decision was taken to establish a colliery spoil tip on the hills overlooking Aberfan. This was viewed as a good location as it lay next to the canal that had been built through the region for transporting coal from the colliery to market. Over the decades that followed seven spoil tips in all were developed here, perched precariously above the town of Aberfan. These tips were filled with an assortment of waste from the coal mines, much of it being fine particles of coal and ash that could not be sold as fuel. This material, if mixed with large enough amounts of water, will effectively turn into dense black slurry. This is what would cause the disaster. A report by British Geological Survey estimated that 2.1 million cubic meters of colliery spoil were deposited in the tips here above Aberfan.[3]
October 1966 was an especially wet month in the Merthyr Vale, particularly the third week of the month. On the morning of the 21st of October workers arrived to the tip and realized that a hole had developed in Tip No. 7 and it was subsiding. They prepared to take preventative measures to stop the situation from deteriorating further, but around 9.15am a huge mound of slurry began to break away from the tip. This set off an avalanche of coal slurry that began to descend rapidly down the hill towards the town of Aberfan below. The main site that it struck was Pantglas Junior School, though some of the streets of the town were impacted too. In places the mound of slurry that was deposited on parts of the town was thirty foot high, over nine meters. Witnesses later reported on a deafening roar as the material came down the hill.[4]
Rescue efforts were underway by as early as 9.45am and scores of people would eventually be taken to the local hospitals. However, many bodies were trapped beneath the debris and slurry. At the same time, residual slurry continued to pour down into the town, the result of a broken water main that continued to leak additional liquid onto the tip. It was much later that day before the situation was brought partially under control and the process of picking through the ruins of the school and parts of the town would continue into early November. The Aberfan disaster remains the largest mining disaster in British industrial history. In the inquiry which ensued it was determined that the incident was primarily to be blamed on poor planning in placing the spoil tips on a hillside above the town and next to natural spring waters, as well as negligence on the part of the colliery workers in charge of the tip.[5]
Extent of migration associated with the Aberfan disaster
The disaster had destroyed many homes and the survivors were left traumatized. It was not properly understood at the time, but today they would be quickly diagnosed as suffering from Post-Traumatic Stress Disorder (PTSD). Given all of this, many people chose to leave Aberfan altogether and start a new life elsewhere. Others who were children at the time of the disaster in 1966 left when they became adults and later cited the trauma of the colliery tip collapse as a reason for doing so. Thus, while the disaster was not an event which led to mass migration, it did cause a change in demographics in this part of south Wales in the long term.[6]
Demographic impact of the Aberfan disaster

The most notable demographic impact of the Aberfan disaster was the death of 144 people in the town. 28 of these were adults and 116 were children, as the local school was the worst affected area. In the long run the town’s population declined. Over 5,000 people lived in Aberfan when the disaster occurred in 1966. Today the population is not much more than half this figure (closer to 3,500 when the surrounding countryside of Aberfan is taken into account), although it is difficult to precisely identify the extent to which the disaster was responsible for this decline.[7] Industrial towns that were the site of coal mines, steel factories and the like across Britain have generally declined in the second half of the twentieth and early twenty-first centuries as the industrial basis of the British economy has been dismantled. Thus, while the Aberfan disaster was doubtlessly partially responsible for the decline of the town of Aberfan, it was just one factor involved in that process.[8]
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See also
Explore more about the Aberfan disaster
- England & Wales, Birth Index, 1837-2005 records collection on MyHeritage
- England & Wales, Marriage Index, 1837-2005 records collection on MyHeritage
- England & Wales, Death Index, 1837-2005 records collection on MyHeritage
- England & Wales Births, GRO Indexes, 1911-1954 records collection on MyHeritage
- England & Wales, Wills and Probate Administrations, 1996-2023 records collection on MyHeritage
- Researching Your Ancestors in England and Wales at Legacy Family Tree Webinars
- Burials and Burial Grounds of England and Wales at Legacy Family Tree Webinars
References
- ↑ https://www.smithsonianmag.com/history/true-story-aberfan-disaster-featured-crown-180973565/
- ↑ Ieuan Gwynedd Jones, ‘The Election of 1868 in Merthyr Tydfil: A Study in the Politics of an Industrial Borough in the Mid-Nineteenth Century’, in The Journal of Modern History, Vol. 33, No. 3 (September, 1961), pp. 270–286.
- ↑ https://www.bgs.ac.uk/case-studies/aberfan-1966-landslide-case-study/
- ↑ https://www.theguardian.com/culture/2016/oct/09/aberfan-50-years-owen-sheers-the-green-hollow-film-poem
- ↑ https://www.thebritishacademy.ac.uk/publishing/review/12/lessons-aberfan-disaster-and-its-aftermath/
- ↑ https://www.bbc.co.uk/news/uk-wales-58874233
- ↑ https://www.citypopulation.de/en/uk/wales/merthyr_tydfil/W45000454__aberfan/
- ↑ https://wcpp.org.uk/commentary/how-did-we-get-here-and-how-can-we-build-on-it-seven-chapters-that-shape-the-welsh-economy/