Gresford Colliery commenced sinking in 1908 and produced its first coal in 1911. The mine had two shafts, some 60m apart and each sunk to a depth of 690m: the downcast (north), which was known as the Dennis and the upcast (south), which was called the Martin. Coal was wound at the Dennis and materials at the Martin shaft. Men were raised and lowered in both shafts. The Dennis section was the scene of one of the worst mining disasters in the country when on 22 September 1934 there was a major underground explosion; that and the subsequent fire eventually killed 266 miners. The mine was re-opened six months after the disaster and coal production resumed early in 1936, however, the Dennis section never reopened and the bodies of 254 victims there were sealed in. The colliery closed in 1973, the site was cleared and is now occupied by Gresford Industrial Park. A monument (nprn 407803) was erected in the grounds of Gresford Colliery Club to commemorate the disaster and record the names of those who died.
B.A.Malaws, RCAHMW, 12 June 2008.