The younger boys who worked at the mine were called breaker boys. They did not actually work in the mine itself. They sat on long benches while coal flowed along beneath their feet and picked out the bits of rock from the coal. These places were poorly lit, and the boys had constant coughs because of the dust. The moving coal would often cut their fingers, and they could hardly stand up staight because of leaning over the coal for so many hours each day. Also, boys would sometimes fall and get smothered or crushed in the huge piles of coal. Worse yet, when the boys turned twelve they would be sent down into the mines where there was a constant threat of cave-ins and explosions.
[Department of Commerce and Labor. Children's Bureau. (1912 - 1913)]