Aberfan schoolkids mark 50th anniversay
20 October 2016 Last updated at 13:45 BST
Friday 21 October 2016 marks the 50 year anniversary of the Aberfan disaster in Wales.
A huge coal waste tip piled high above the village of Aberfan suddenly collapsed and slid down into the village, covering houses and the local school.
The tragedy shocked people all over the world, as 144 people were killed in the disaster.
School children in Aberfan explain to Newsround how they are marking 50 years of the Aberfan disaster.