Today marks the 50th anniversary of the Aberfan disaster, with a minute’s silence being held in Wales.
Events will also be held throughout the day at Aberfan Cemetery to commemorate the disaster, which took place on October 21 1966.
The disaster was caused by a landslip at the top of Mynydd Merthyr, a mountain above the mining village of Aberfan. This led to a huge tip - waste built up from the mine - plunging down the mountainside and engulfing the village below.
At around 7:30am mine workers found the tip had sunk by three metres at the top of the mountain. But by the time a call could be made to tell people to stop adding to the tip, it had sunk by six metres. The landslip had already begun and there was no stopping it.
A total 150,000 tonnes of slurry slid down into Pantglas Junior School and people's houses at around 9:15am, when the school's pupils were having their first lessons of the day. It only took five minutes for the coal tip to bury the school and the surrounding houses. A total of 144 people, including 116 children, died.
The aftermath of the disaster witnessed a huge amount of heroism and selflessness. Emergency services and local people helped in the rescue effort to find those buried alive, with coal miners from Mountain Ash and surrounding areas joining the attempt to find survivors. Rescuers formed a sort of conveyor belt of "bucket brigades" to move waste away quicker, and even stood silently at times in an attempt to hear calls from under the slurry.
Yet the tragedy might have been avoided altogether had a series of warnings not been avoided.
A tribunal was heard weeks after the event, and findings published the next year blamed a "bungling ineptitude by many men" that had failed to heed clear warnings about the tip, perched precariously on the side of Mynydd Merthyr.
Just two years before the disaster two mothers had given a petition to the school, with concerns over flooding, and also passed it to the local council. Yet no action was taken.
In 1964, local councillor Gwyneth Williams had also said if the tip were to move [in an event such as a landslip] it would threaten the school. Waterworks engineer DCW Jones also sent a letter to a colleague and the National Coal Board in 1963, expressing concern about the tip.
In the aftermath of the disaster, one witness said the tip "had been piling higher and higher and with a stream filtering through beneath it. It was always liable to shift. Now it has happened, with these terrible results.”
Even those working at the school had foreseen what was to happen. The wife of David Benyon, the schoolmaster at Pantglas, said the building would bear the brunt if the tip ever slipped down the mountainside. Yet no-one had listened to his dire prophecy - only after Benyon had died trying to save his pupils did anyone take any notice.