A 'dark glistening wave' and 116 children buried alive: The true story of The Crown's Aberfan disaster.

The Queen says her handling of the Aberfan disaster was the biggest regret of her reign.

What happened?

It was 9.15am on October 21, 1966, and roll call was just beginning for the students of Pantglas Junior School in Aberfan, Wales. It was the last day of school before the mid-term break, and it was only a half-day. The students had less than three hours before they could run off out the school gates and enjoy their holidays.

And then an avalanche hit, destroying the school and killing 116 children and five teachers.

This is the Aberfan disaster, which features in the third season of The Crown. Queen Elizabeth has reportedly described her handling of the disaster as the biggest regret of her reign.

How did it happen?

Aberfan is a village near the bottom of the Taff Valley. In 1966, it had a population of 5000, with many of the residents being employed by the nearby coal mine. Several spoil tips from the coal mine – huge piles of debris – were located directly above the village. One of them, Tip 7, was on top of an underground spring. The tip was 34m high. The danger had been discussed with the National Coal Board, but no action had been taken.

After three weeks of heavy rain in October 1966, Tip 7 began to move. A worker noticed it at 7.30am on October 21. Nothing was done.

Less than two hours later, a “dark glistening wave” of water-saturated debris poured down the hill, sounding like thunder, destroying two farm cottages and then hitting the school, knocking down buildings and burying everything under almost 10m of thick sludge, which soon started to solidify. Another 18 houses in the village were also destroyed.

What was the total death toll?

Not all the children at the school died. A 23-year-old teacher, Hettie Taylor, managed to get her students out of the classroom while the walls were bulging and cracking.

"I want you to leave the classroom,” she told them calmly. “I want you to walk straight out to the yard. Don’t look back."

Meanwhile, dinner lady Nansi Williams had been collecting money when she heard the thundering sound and felt the school began to shudder. There were five children lined up in front of her, and she told them to get on the ground, then threw herself on top of them. She died, but all five of them lived.

“It's only down to Nansi that I'm here today,” one of the children, Karen Thomas, told the BBC on the 50th anniversary of the disaster. “I'll never be able to thank her enough for saving us."

Those five children were lucky. There were very few survivors pulled from the wreckage of the school, despite the villagers – many of them parents – digging frantically with their bare hands or any tools they could find.

“Every now and then, the rescue teams called for silence in case we could hear voices underneath the mountain of rubble,” journalist Gwyn Llewelyn later remembered. “But after the first few minutes, we heard nothing.”

After 11am, no one was found alive.

All up, 144 people died in the disaster. Of those, 116 were children.

What was the reaction to the disaster?

Thousands of people came to Aberfan to help in any way they could, although many just got in the way. The chairman of the National Coal Board, Lord Robens, didn’t turn up on the day of the disaster, instead going to the University of Surrey to receive a chancellorship.

The Queen’s brother-in-law, Lord Snowdon, turned up the next morning, and wrote to Princess Margaret, "Darling, it was the most terrible thing I have ever seen".

Prince Philip visited the same day. But the Queen didn’t go. According to Sally Bechdel Smith’s biography Elizabeth The Queen, she was concerned she would be a distraction.

“People will be looking after me,” she said, according to Smith. “Perhaps they'll miss some poor child that might have been found under the wreckage.”

It took a week to recover all of the bodies. A mass funeral was held where 81 of the children were buried in two massive trenches.

The Queen turned up eight days after the disaster. A young girl gave her a posy of flowers reading, “From the remaining children of Aberfan”. She cried – one of the few times she ever shed tears in public.

Many years later, it was revealed that the Queen felt the biggest regret of her reign was not visiting Aberfan immediately after the disaster.

"If the Queen does regret not coming here straight away, I think that is misplaced," Jeff Edwards, one of the surviving schoolchildren, told the South Wales Echo in 2002. “When she did arrive she was visibly upset and the people of Aberfan appreciated her being here. She came when she could and nobody would condemn her for not coming earlier, especially as everything was such a mess."

People from around the world donated a total of £1.75 million to the people of Aberfan. However, the money was controlled by a commission, who were reluctant to hand much over to the families. At one point they said that each family who had lost a child had to be individually judged, "to ascertain whether the parents had been close to their children and were thus likely to be suffering mentally".

At an inquest into the disaster, the National Coal Board tried to explain it away as a freak accident. However, the tribunal found it was “a terrifying tale of bungling ineptitude”.

Melvyn Walker, a student who managed to escape the school by smashing a window, recently spoke about the disaster for the first time, 50 years after it had happened.

He says he couldn’t go to school for two years afterwards and never held down a job or got married. He still gets flashbacks from the sound of children playing.

“I get very anxious even to this day,” he told WalesOnline. “If I hear children’s voices it takes me straight back.

“I would say it has spoilt my life.”