ABSTRACT
Senghenydd had claimed 81 miners' lives in an explosion in May 1901. This time the whole mine was destroyed. Anyone underground who survived the explosion would probably have been suffocated by after-damp', an unbreathable gas consisting mostly of carbon dioxide and nitrogen dioxide left after the explosion had consumed most of the oxygen in the atmosphere. Gresford Colliery was one of the deepest Welsh coal mines, an old pit dating from the early Victorian era. It had two separate shafts, known as the Dennis and the Martin, both descending over 2,200 feet and about 150 feet apart. Over many years the workings had fanned out a good distance from the shafts. While the death toll was low compared with the disasters of the past, this tragic incident provoked a furious outcry from the mining unions and experts about the system of roof support that had been introduced at Bilsthorpe and elsewhere.
