The King, Queen and Prince of Wales will join politicians, survivors and bereaved families to mark the 60th anniversary of the Aberfan disaster, remembering 116 children and 28 adults killed.
Almost a whole generation was wiped out on 21 October 1966 when 150,000 tonnes of coal waste slid down a hillside and engulfed Pantglas Junior School.
Following days of heavy rain, excavated mining spoil from Merthyr Vale Colliery became loose and came crashing down the slope.
This waste had been piled high above Aberfan on Mynydd Merthyr for years, despite the existence of multiple underground springs below.
Pupils inside Pantglas Junior School were preparing for lessons when 1.5 million cubic feet of liquefied slurry hit the school and nearby homes.
Approximately half of the junior school's children died in the disaster, which occurred on their final day before half term.
Charles, Camilla and William will visit the Aberfan Memorial Garden, which is located on the site of the junior school, and the nearby Aberfan and Merthyr Vale Community Centre.
They will join survivors, bereaved parents and members of the community to pay tribute to all those who lost their lives.
A short prayer and a moment of silence will be held, during which The King and The Prince of Wales will lay wreaths, and The Queen will place a posy.
At the community centre the royal party will meet retired members of the emergency services who helped in the hours and days after the disaster.
They will then spend time with survivors, bereaved parents, and siblings of those who died.
Later, Prince William will visit Ynysowen Community Primary School where he will unveil the Aberfan Memorial Tree, a new sculpture created to commemorate the anniversary.
Queen Elizabeth II visited eight days after the tragedy and shortly after a mass funeral had taken place.
Her decision not to visit sooner was said to have been one of the greatest regrets of her reign.
She returned to Aberfan three more times during her life and opened Ynysowen Primary School in 2012.
Charles, who was then the prince of Wales, visited Aberfan in 2016 and privately laid a wreath bearing the words “Er bythol gof a chyda’r cydymdeiumlad dwysaf”, meaning “In continuing memory and deepest sympathy”.
He planted a sweetgum tree in the Aberfan Memorial Garden and spoke to survivors at a reception before delivering a speech that included a message from the late Queen.
William previously met survivors of the Aberfan disaster when he visited with the Princess of Wales in 2023.
First Minister Rhun ap Iorwerth, who will attend the remembrance event, described Aberfan as “one of the darkest days in our nation’s history”.
“The events of 21st October 1966 devastated the community of Aberfan. It robbed a generation of its children of their futures in a matter of moments,” he said ahead of the anniversary.
“Hearing stories of that day is an early memory that left a deep and lasting effect on me.
“It brought home to me the horror of that day for all those who were there, and who lived to bear witness to what happened.
“The story of Aberfan will never be forgotten. It is a story of the most terrible loss and grief. But also a story of the resilience of a community over six decades.”
Ahead of the milestone, Stephen Kinnock, Secretary of State for Wales, said: “The community of Aberfan suffered a loss so profound that it remains etched into the memory of our nation.
“Today, we remember each and every one of them.
“Aberfan is a community that has shown extraordinary strength, resilience and dignity in the face of such devastating tragedy, coming together time and again to ensure that all who were lost there are never forgotten.”
Archbishop of Wales Cherry Vann said: “Today, as we commemorate that heartbreaking day, our thoughts and prayers are with the people of a community which has shown, in face of unbearable suffering, the most inspiring resilience and strength.
“We offer our prayers for all across Wales and beyond who are touched by today’s commemorations.”
Coal bosses had been warned about “flowslides” prior to the disaster and, despite a 76-day public inquiry, no-one faced prosecution or lost their job.
Local residents were left with no choice but to take £150,000 from a memorial fund to pay for the clean-up bill. This was eventually returned after decades of campaigning.
On Monday, Prime Minister Andy Burnham visited Aberfan, where he spoke with survivors and bereaved families and laid a wreath in memory of those who died.
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