Knox Mine disaster [Coal]

Physical and cultural impacts:

In January 1959, miners working the coal mine through the Pittston bed beneath the Susquehanna River compromised the riverbed. The ice-heavy river broke through its dangerously thin bed and drained into the Knox Mine. Although mining operations were legally restricted within 35 feet below the riverbed, by the day of the disaster, the Pittston bed had been excavated to within 2 feet below the river. Twelve men are entombed in the mine.

Though the mine is now sealed off, ground water continues to flow and seep through the old shafts and emerge into the Susquehanna. When water flows through coalmines, it dissolves the coal, releasing sulphuric acid. The acid reacts with soluble iron in the river, producing a yellow-orange material commonly called yellow boy.

From top:

Top two: yellow boy covers the rocks, banks, river bed of the Susquehanna; third image: the line between acid mine drainage and natural river is clear; bottom: a box car, driven into the mine in 1959 in an attempt to plug the riverbed, missed the sinkhole and now sits beside the river bank.