Aberfan Landslide – South Wales – Britain – October 21, 1966

Aberfan, in south Wales, Britain, was a coal mining area. Coal waste was stored on a neighboring site above the elevation of the town. Inadequate care of this waste site caused the devastating landslide.

On the morning of October 21, 1966, as school began in the village of Aberfan, South Wales, a heap of coal waste that stood hundreds of feet above the village slipped and swept down on to the school and a row of small houses. One hundred and forty-four were killed by the mass of rock, most of them school children. It was an accident that should never have happened because the heap, known as tip number seven, was known to be unstable. Neighboring mines closed down as soon as it was known what had happened and miners joined in efforts to free the ones buried beneath the rubble.

Every mine has a waste heap—a deposit of the material brought to the surface with the coal then left behind as the coal is taken away. Aberfan was located in one of Britain’s biggest coal-mining areas and waste heaps dotted the landscape around it. It was a small village on the banks of the River Taff in South Wales and above it towered the steep slopes of Merthyr Mountain, the site for disposal of the wastes from Merthyr Vale Colliery. Perhaps the very familiarity of these heaps made people less sensitive to their danger. The one that overshadowed Aberfan had been around for about eight years.

The accumulation of waste heaps dated from the early 1900s when mechanical methods of mining became common. It was easy to extract smaller dirtier coal seams by these methods and as a result there were larger than usual heaps of waste. In other countries such material was often taken back down to fill in discarded shafts. In Britain the tendency, at least in this part of the country, was to create artificial hills. Later they were often seeded with grass or shrubs to mask their unsightly appearance. There were no clear regulations in place at the time of Aberfan for periodical inspection of these waste deposits and this was one of the weaknesses later addressed by the Public Inquiry.

Number seven tip was first used in 1958. It lay across some streams from the mountain, unlike others that stood between streams, and this should have alerted authorities immediately. There were several instances in the past when water flows beneath tips had triggered small landslides. As far back as 1927 a mining expert had given a lecture on the dangers of allowing water to accumulate or flow beneath tips. He pointed out that if the South Wales mining authorities did not pay for drainage to draw water away from tips they would have to pay for the higher costs of landslides at a later time. The priority, however, among mine managers was coal and little thought was given to the design of tips. The men who selected the location of number seven tip had no expertise for making that choice.

Waste went up the sides of Merthyr Mountain on rail tracks and then was emptied sideways and backwards on to the tip which gradually rose in height. It was an efficient and cheap storage method. Land costs were negligible and because of the slope more material could accumulate than on level ground before the height raised questions of instability. By the time of the accident, tip seven was over a hundred feet high. Unlike previous heaps it contained tailings—the throwaway material from a frothflotation process that extracted additional fuel from the mine’s output. These tailings tend to harden when dry so workers soaked them before taking them up the slope for ease of handling and dumping. By the time of the accident large quantities of tailings had been deposited here.

The critical factor with tailings is their ability to lower the angle of rest that they finally assume. Because they were made almost fluid in order to transfer them to the tip they flow and create gentle slopes, usually as low as a four-degree angle instead of the twenty-seven degrees that occurs with dry material. All kinds of regulations had been circulated regarding the danger of gentle slopes giving way. Plans were in place to remove tailings permanently from these tips because of this danger and deposit them underground. Nevertheless, the low priority given to the care of waste heaps delayed action on this recommendation and tailings continued to accumulate on tip seven. Local residents continued to express their fears especially after a slide in 1963 washed away the foot of tip seven leaving a steep eighty-foot-high face.

In the months before it finally collapsed, number seven tip displayed further evidence of its basic instability. Its front edge moved downhill thirty feet in six months and its interior collapsed several times over the same period of time. These serious indicators of danger were reported but as in earlier warnings nothing was done about them. On the morning of the massive slide, one more report of this kind was made by workers on the site and this time a manager decided he would start another tip on the following Monday, three days later. He did not have the opportunity to do this but there was more to this event than his reaction. The same decision had been made, for the same reasons, a year before, but was delayed because of difficulty getting the right gauge of railway track.

Within an hour of the manager’s response to the workers, 140,000 tons of saturated black rock and mud roared down the mountainside. Men working near the heap saw it begin to slide away but they were not able to see what was happening down the slope because of a heavy fog that day. They also knew that this heap had a history of giving way from time to time and nothing very serious had happened when it slipped in 1963. Two water mains were broken by the slide and this added momentum to the mass movement of material. The slide began shortly after nine and by eleven o’clock schools and homes had been overwhelmed and all within killed. Intense activity was triggered at once throughout the area especially when it was known that children were the principal victims.

One man whose daughter was reported dead ran to the school from his place of work three miles away and dug down into the ground all day until forced to stop by darkness. At times there were as many as 5,000 people digging away to reach the school beneath. The high level of noise made it difficult to hear cries of help from below. Army units were brought in to control movements of people and cars specially to ensure easy passage for ambulances. Rescuers went on working through the night after floodlighting was brought in. All the time there was the fear of further slippage from above because the rain had been heavy for the previous few days.

For almost three months, the inquiry into Aberfan held meetings and heard from numerous witnesses. The National Coal Board (NCB) bore the brunt of the blame, mainly for continuing indifference to the danger signals that had been obvious for so long to so many. Their inspectors, said the report, were like moles being asked about the habits of birds. No inspector had visited Aberfan for four years prior to the disaster. It was no surprise for the public to be told in the final report that the accident was due to bungling ineptitude by men who were charged with tasks for which they were totally unfitted. A completely new organizational structure was recommended for the NCB to ensure proper care and safety at all levels.

The inquiry urged the immediate digging of tunnels inside the heaps in order to remove the danger of waterlogged slides. It also proposed the re-contouring of these same heaps to remove what had become an eyesore to the villagers. The worst damage of all came much later, the psychological effects on the villagers. More than 150 residents, half adults and half children, needed psychiatric help. Large numbers experienced nightmares for years. Ten years after the tragedy Merthyr Mountain looked very different. All the tips had disappeared and a special hillside cemetery and memorial stood at Aberfan commemorating the victims of the 1966 landslide.

The events at Aberfan featured a few years later at a U.S. coal mining location involving the Buffalo Mining Company, a subsidiary of Pittston Coal, one of the nation’s biggest coal producers. This company began using Buffalo Creek as a dump in 1957 just as the companies in Aberfan had done on higher ground. Over the succeeding years it made use of additional sites farther upstream. By the early 1970s the creek consisted of a series of dams behind each of which was a pool of black waste slurry. The Buffalo Mining Company, like others in the region, had a history of ignoring environmental safeguards. In 1967, the U.S. Department of Interior warned state officials that Buffalo Creek dams and twenty-nine others throughout West Virginia were unstable and dangerous. This warning was the result of the Department’s intensive studies throughout the state, inspired by the news of the accident in Aberfan, Wales, a few years earlier.

The new method of extracting coal in use by the Buffalo Company had been in operation for some time. It is known today as strip mining, reaching coal from the surface instead of from underground. It can be done where coal seams are close to the surface. The earth and overlying rock is removed and the coal seam is then broken up into smaller pieces by explosives and taken to nearby preparation plants for refining. The coarser waste rock is piled up next to the mined area and the finer coal wastes, including the tailings from the preparation plant, are discharged into an impoundment pond behind the heap of waste rock. Environmentalists are opposed to this method of mining because it destroys large tracts of the land. Mine companies contend that they will restore the ground surface to its original appearance once the mine is closed down.

Mountaintop mining is a variant of strip mining and is common in West Virginia. Here the valleys and their streams adjacent to mining operations serve as repositories so the waste materials are dumped there. Buffalo Creek, in Logan County, is one valley used in this way. This creek flows through sixteen small communities on its seventeen-mile journey to the town of Man. The sides of the valley are steep. The various communities sprang up over the years in response to the changes occurring in the local coal mining industry. From the time of the earliest operations in the 1940s there were many changes in the productivity of the mines with the highest outputs coming in 1970.

Despite frequent warnings in the wake of inspections, nothing was done to make the dams safer. A drainage bypass system that would protect the residential areas was recommended but not done. By February of 1972, concern was widespread as heavy rains deluged the area and the streams and ponds behind the dams and ponds on Buffalo Creek began to rise. These ponds by this time had millions of tons of sludgy material on their bottoms and half a million gallons of waste liquid kept pouring in daily from the preparation plants. The state of West Virginia had cited the coal company in 1971 when a failure occurred in one dam but no action was taken to provide an overflow channel.

Finally on February 26 one big dam on the upper reaches of the creek gave way, taking all the others with it. One hundred and thirty million gallons of water and thirty-five million cubic feet of waste materials roared down the valley at 30 mph. A twenty-five-foot-high tidal wave of slurry, rock, and soil descended on the communities below. There was no time to give warnings to either residents or local authorities; the coal company did not even try. The dam had collapsed at the same spot where it had broken a year earlier. A canyon forty-five feet deep in places was carved out of the valley as home after home was washed away. In all, a thousand dwellings were lost, leaving 6,000 people homeless and 125 dead. Some were able to scramble up the valley sides before the tidal wave reached their location. Others were carried to safety on the tops of their homes as the force of the black water swept the buildings off their foundations. All forms of communication were cut off. This included telephone lines and rail tracks. The high school in Man was set up as a relief center.

Some residents were able to come back and build new homes, aided by modest financial assistance from the coal company. Many of the victims, however, were unhappy with the compensation provided and, aided by a lawyer from a major Washington, D.C. firm, launched a legal claim in federal court. In the course of the legal proceedings it was discovered that this was not the first lethal accident by Pittston and other coal companies in this part of the country. In 1924, a waste pile gave way in Crane Creek, West Virginia, killing seven people and devastating a wide tract of land. Another failure occurred in neighboring Virginia in 1955 when a Pittston Company’s waste pile gave way destroying homes and property. The end result of the legal challenge was an award of $13,000 to each of the six hundred claimants, an award far in excess of the amounts given to those who accepted the coal company’s offer.

It took years to rebuild the communities along Buffalo Creek at a cost to the state of a hundred million dollars. A memorial monument was built and annually the tragedy of 1972 is remembered in a special service. In response to the Buffalo Creek and other disasters, the U.S. Congress enacted the National Dam Inspection Act, authorizing the United States Army Corps of Engineers to inventory and inspect all non-federal dams. In addition, President Carter issued a memorandum on April 23, 1977, directing a review of federal dam safety activities by an ad hoc panel of recognized experts.