In June 1903, at 10:30 AM, an underground explosion occurred in the Hanna No.1 Colliery. The explosion was thought to have originated at the end of the slope, one and a half miles underground, blocking escape for the majority of workers. Of the 215 men on site, only 46 survived - the majority of victims being Finland immigrants and black workers. The town's original gravesite was far too small to handle such a massive body count, and the town was forced to establish the Hanna Cemetery to bury the bodies, three miles outside of the town itself.