Video report by ITV News Correspondent Juliet Bremner
The last survivor to be pulled from rubble of the Aberfan disaster said his childhood ended that day.
Jeff Edwards, who was just eight years old, lost most of his classmates when a coal slip buried his school in the tiny welsh village on October 21 1966.
Speaking on the 50th anniversary of the tragedy in which 116 children and 28 adults died, he told ITV News: "Most of my friends in my class died, so our childhood was over that day at 9.15am.
"Basically we were happy-go-lucky children, looking forward to the half-term holidays, and at 9.15 our childhood stopped".
Mr Edwards said he woke to find one of his classmates dead on his shoulder.
"There was this rumbling sound, which got louder and louder as time went by, and the next thing I remember was waking up.
"When I woke, I found myself covered in this material, with a dead girl on my shoulder.
"I couldn't move and there were screams and shouts which obviously got less and less as time went by."
Despite the heroic efforts of rescuers who dug for hours and formed human chains to remove the waste, Mr Edwards was the last survivor to be pulled out of Pantglas junior school.
He said it is difficult for him to face the anniversary of the disaster every year because he still remembers his former classmates.
The official inquiry blamed the National Coal Board for extreme negligence and it led to new leglislation being passed about public safety for mines and quarries.