In Cheswick, PA in 1904 over 100 men were killed when an explosion ripped through the Hartwick Coal Mine igniting gas and trapping the miners.
Oklahoma mines tended to fill with gas too and these ' windy tunnels' - exploded from sparks, lamps, and other accidental ignitions. Roofs collapsed under the strain of thousands of tons of rock and dirt being bored by ax, pick and dynamite (Coal Mining Disasters).
1892 - Jan. 7, Krebs, I.T. - 100 men killed, 150 injured
1902 - June, Dow, I.T. - 10 killed in the Milby and Dow Company Mine.
1906 - Jan., Poteau, I.T. - 14 men killed
1908 - Aug, Haileyville, OK - 31 miners die in coal mine fire Mine #1 near McAlester in eastern Oklahoma
1910 - April 1 - 6 men die in Great Western Mine # 2
1910 - Oct 19 - Buck, OK - 2 men killed in #6 mine (*)
1912 - Feb. 23, 20-40 men reported dead in coal mine explosion.
Additional mining accidents occur in the 1920s and 1930's, but safety measures improved and there was generally less loss of life.
(*) - One book on ghost stories, Haunted Homeland, cites 'Mine # 6' in Buck, OK but mis-dates the event and mis-identifies victims.