A half-hour before midnight on June 8, 1917, a fire broke out in the North Butte Mining Company's Granite Mountain shaft. Sparked more than two thousand feet below ground, the fire spewed flames, smoke, and poisonous gas through a labyrinth of underground tunnels. Within an hour, more than four hundred men would be locked in a battle to survive. Within three days, one hundred and sixty-four of them would be dead.