Landslide, also referred as landslip is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments. Although the action of gravity is the primary driving force for a landslide to occur, there are several other contributing factors affecting the original slope stability. This report explains how the Aberfan disaster happened.

In 1966, apart from industrial waste’s negative impact on the environment and the eco-system, a tragic and needless accident was witnessed at the Welsh mining village of Aberfan in 1966 resulting in the loss of human life.Sitting at an elevation higher than that of Aberfan, rested a depot for coal and unwanted rock – a sort of waste site. On 21st October 1966, a heavy rain followed by a “slab heap” of rocks slid down the hill, pummeling a children’s school at the foot of the hill. The depot had a hill underneath it which lead into the town itself.144 people were killed and out of which 116 were children. The horror turned to outrage on discovering that the authorities were well aware that the depot was unsafe and finally the Aberfans future generation had been sacrificed due to corporate negligence.

The Merthyr Mountain to west of Aferban, towered huge deposits of colliery spoil. A spring and stream ran under one of the tips. Heavy rain before disaster had soaked into tip and sandstone.With surface spring blocked by soil and impermeable rock underneath, water could not drain away and the ground became saturated and unstable.

On 21st October morning, mine workers arriving at tip found that it had sunk around 3 meters overnight.With no phonelines to office, workers went down the mountain on foot to report problem. By the time order was given to stop adding to tip, it had sunk 6 meters. Fifteen minutes later, the tip number 7 gave way and slid down hillside towards Aferban.

The slide overwhelmed two farm houses, crossed deserted canal and railway before destroying school and 18 more houses. Afraid of the fact that the tips that remained could slip again, the villagers wanted them to be removed.When their demands weren't met they dumped bags of slurry in the Welsh office and the government finally agreed for their removal, but the village had to pay £150,000 from the disaster fund towards the work.The disaster caused division amongst those who lost family and those whose loved ones survived, a split that time has helped to heal.

Cliff Minett fully understands this.While his daughter Gaynor Madgewick was pulled out alive, another daughter and son died at the school that day. He adds that "Saturday is no different from any other day for us. It doesn't matter if it's one year or 40 years on - the pain is just the same, the memories as clear today as they were then.Some will go to the cemetery to remember - others will stay at home, but we will never be able to forget what happened in Aberfan that day."