Mining disaster memorial unveiled in Senghenydd A day of events marking the 100th anniversary of Britain's worst mining disaster is taking place in Senghenydd. Hundreds turned out in the streets of the Caerphilly county village where an explosion killed 439 miners and a rescuer at the Universal Colliery on 14 October, 1913. A national memorial has been unveiled to mark the event and other mining tragedies in Wales. Patron Roy Noble made a speech before helping unveil the bronze statue of a miner and a rescuer.