To understand this story, you need to know that South Wales used to be a very important coalmining area. The mines in South Wales produced steam coal, which was used to fire boilers in ships and factories, and anthracite, which is a very high quality coal used for heating homes and other buildings. In the early part of the last century, there were 620 collieries (coal mines) in South Wales, employing nearly a quarter of a million people. Now, when coal is brought out of the ground it is mixed with rock and dirt and coal which is too fine to be used. This is called colliery waste, and it was normal for the colliery waste to be dumped in a huge heap – a spoil heap or tip – near to the mine. In the coal mining valleys of South Wales, these tips were often built on the sides of the valleys. One such tip was on the hillside overlooking the village of Aberfan.

　　October 1966 was a very wet month. The rain soaked into the spoil heap above Aberfan until it was full of water. The tip began to move. It slid down the hill and into the village. It swept over houses and the primary school. In the school, lessons had just begun. It was the last school day before the half-term holiday. Altogether, 143 people died in the Aberfan disaster, including 119 children – that is, over half of the children at the school.

　　I can remember the newspaper reports the next morning, and how horrified everyone was by what had happened. One picture was in all the papers – a picture of a policeman carrying a small girl from the wreckage of the school. I have put it on the podcast website. The photographer who took the picture was only 18 years old at the time.

　　There was a formal enquiry to find out why the disaster had happened. It emerged that junior officials in the National Coal Board had been worried by the condition of the Aberfan spoil heap, but their bosses had done nothing. Many people were shocked that no-one was prosecuted, or even lost their job, because of the Aberfan disaster.

　　If you visit the area today, you will see little sign of the coal industry. There is only one working deep mine left in South Wales. Many of the places where the old collieries used to be are now supermarkets or new housing estates. The colliery tips have been levelled. But the people have not forgotten what happened that day 40 years ago.