On May 12, 1942, a worker in the Christopher No. 3 mine at Osage—just outside Morgantown—left a ventilation door open, and methane accumulated in a dusty area of the mine. At 2:25 in the afternoon, an electric arc from machinery set off an explosion that coursed through three sections of the mine, killing 53 men, destroying ventilation equipment, and causing roof falls. Three others later suffocated in the noxious ‘‘afterdamp’’ gasses. Several miners managed to reach safety through a return airway.