1966 at 09:15 - 144 people, 116 of them children, were killed when a tip of coal waste slid onto the village of Aberfan in South Wales.
At the Tribunal of Inquiry into the Aberfan Disaster, the NCB was found responsible for the disaster, due to "ignorance, ineptitude and a failure of communication". No NCB employee was fired, demoted or even disciplined.