John Humphrys: What we owe the people of Aberfan

"If Aberfan stands for anything today, apart from unimaginable grief, it stands as a reminder of this; authority must always be challenged."

Fifty years after reporting on the Aberfan disaster, John Humphrys returns to the village where 116 children and 28 adults died.

(Picture: a miner in Aberfan Credit: Getty Images)