The Susquehanna River broke into the mines during Knox Mine Disaster in 1959, flooding much of the underground mine tunnels. Another important event that elevated water levels underground was the Agnes Flood, in 1972.
The Susquehanna River broke into the mines during Knox Mine Disaster in 1959, flooding much of the underground mine tunnels. Another important event that elevated water levels underground was the Agnes Flood, in 1972.