During the night shift the flame of a carbide lamp accidentally set fire to the uncovered and frayed insulation
of an armored power cable near the 2,400-foot level of the Granite Mountain shaft. The highly flammable oiled fabric set fire to the shaft timbers, and inasmuch
as this was a downcast shaft, the fire spread rapidly and soon filled the mine workings with smoke and gas.
At the time, 410 men were working underground, 247 of whom escaped by various means, but most of the 163 remaining probably were overcome soon after the fire began and perished. Only two
men were actually were burned.
The immediate effect of the fire was the reversal of air currents in the shaft; the ultimate effect was great loss
of life and the destruction of the main hoisting shaft, putting it temporarily out of service. The work of rescue and fire fighting continued
for eight days.
Historical Summary of Mine Disasters in the United States - Volume III