At 9.15 am on Friday, October 21, 1966 a waste tip slid down a mountainside into the mining village of Aberfan, near Merthyr Tydfil in South Wales.
It first destroyed a farm cottage in its path, killing all the occupants.
At Pantglas Junior School, just below, the children had just returned to their classes after singing All Things Bright and Beautiful at their assembly. It was sunny on the mountain but foggy in the village, with visibility about 50 yards.
The tipping gang up the mountain had seen the slide start, but could not raise the alarm because their telephone cable had been repeatedly stolen.
(The Tribunal of Inquiry later established that the disaster happened so quickly that a telephone warning would not have saved lives.)
Down in the village, nobody saw anything, but everybody heard the noise. Gaynor Minett, an eight-year-old at the school, remembered four years later:
‘It was a tremendous rumbling sound and all the school went dead. You could hear a pin drop. Everyone just froze in their seats. I just managed to get up and I reached the end of my desk when the sound got louder and nearer, until I could see the black out of the window. I can’t remember any more but I woke up to find that a horrible nightmare had just begun in front of my eyes.”
The slide engulfed the school and about 20 houses in the village before coming to rest.
‘Then there was total silence.’
George Williams, who was trapped in the wreckage, remembered that ‘In that silence you couldn’t hear a bird or a child’.
144 people died in the Aberfan disaster: 116 of them were school children.
About half of the children at Pantglas Junior School, and five of their teachers, were killed.
A shy and fragile leaf now greens
In a bright and plastic room
On tender stems it offers forth
To cast its earthen womb
Fed by a valley’s tears
That watched it leaf and grow
To tell of ones that sleep the night
In Aberfan below
One day those sleepy flowers
Will leave that sunsealed land
And wink away the night
That no one understands
To tell us why that summer fades
In a single afternoon
And why that day in Aberfan
Did autumn come too soon.