On March 10, 1920, in Pachuca, Mexico, the Compañía de Santa Gertrudis—the largest employer in the region, and a subsidiary of the United States Smelting, Refining and Mining Company—may have committed murder. The alert was first raised at six in the morning: a fire was tearing through the El Bordo mine. After a brief evacuation, the mouths of the shafts were sealed. Company representatives hastened to assert that “no more than ten” men remained inside the mineshafts, and