The Knox Mine disaster was a mining accident that took place in the Greater Pittston, Port Griffith, Pennsylvania village of Jenkins Township, Pennsylvania, near Pittston, on January 22, 1959.
The River Slope Mine, an anthracite coal mine owned by the Knox Coal Company, flooded when coal company management had the miners dig too close to the riverbed. Tunneling sharply upwards toward the Susquehanna River, the miners reduced the thickness of rock between the mineshafts and the river bed to about 6 feet (1.8 m) -- 35 feet (10.6 m) was considered the minimum for safety. This caused the waters of the river to break through into the mine.
It took 3 days to partially plug the hole in the riverbed, which was done by dumping railcars into the whirlpool formed by the water draining into the mine.
12 people died; 69 others escaped. One miner, Amadeo Pancetti, was awarded the Carnegie Medal for leading 32 miners to safety. The bodies of the 12 who died were never recovered, despite efforts of divers and an attempt to pump the water out of the shafts.
Source: Wiki
Full report
[url]http://www.msha.gov/District/Dist_01/Reports/Knox/contents.htm[/url]