|Local miners joined in the rescue effort in a desperate bid to find survivors
Artificially 1969:More than 130 people, mainly children, have been buried by a coalslagheap at Aberfan, near Merthyr Tydfil in Wales.
1966: Coal tip buries children in Aberfan
At least 85 children have been confirmed dead after the tip engulfed a school, some terraced cottages and a farm in just five minutes. Many more are missing or injured.
At first the rescue was held up by fog, the same fog that delayed 50 children travelling to the Aberfan school by bus from the neighbouring village of Mount Pleasant.
About 2,000 rescuers are now working under floodlights in the hunt for survivors, despite the danger caused by the still shifting slag tip.
The tragedy happened at 0915, just as the pupils of Pantglas Junior School were about to embark on their first lessons.
Some children were still in the playground, others were filing in to classrooms ready for register.
Dilys Pope, aged 10, said, "We heard a noise and we saw stuff flying about. The desks were falling over and the children were shouting and screaming."
In one classroom 14 bodies were found and outside mothers struggled deep in mud,clamouringto find their children. Many were led away weeping.
The deputy head teacher, Mr Beynon, was found dead. "He was clutching five children in his arms as if he had been protecting them," said a rescuer.
Three people died in the farm hit by the disaster and a pregnant woman whose son was killed in the tragedy went into labour when she heard the tragic news.
As people arrived at the scene, they could hear the cries of those still trapped on the fringe of the coal waste.
One of the biggest problems facing the rescue operation was getting vehicles to the site which is located in a cul-de sac.
Many local miners shovelled to get the debris clear and worked non-stop for 10 hours, including one whose young daughter was thought to be dead.
George Thomas, Minister of State for Wales, said: "A generation of children has been wiped out. There is an abundance of tips of this sort in Wales, and we shall be looking for the possibilities that it could happen again."