On January 27, 1891, an explosion in the nearby Mammoth Number 1 Mine of the H.C. Frick Coke Company killed 109 coal miners. Seventy-nine of the dead were buried in a mass grave here in Saint John's Cemetery. This disaster was the worst one known to that time in a bituminous coal mine in Pennsylvania. It led to state legislation strengthening the program of mine safety inspections in the bituminous fields.