The Knox Mine disaster was a mining

Mining

Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...

 accident that took place in Port Griffith

Port Griffith, Pennsylvania

-External links:* at Mine Country History...

, a town in Jenkins Township, Pennsylvania

Jenkins Township, Pennsylvania

Jenkins Township is a township within the Greater Pittston area of Luzerne County, Pennsylvania, United States. The population was 4,584 at the 2000 census. The township is adjacent to the small city of Pittston...

, near Pittston

Pittston, Pennsylvania

Pittston is a city in Luzerne County, Pennsylvania, United States, between Scranton and Wilkes-Barre. It gained prominence in the late 19th and early 20th centuries as an active anthracite coal mining city, drawing a large portion of its labor force from European immigrants. The population was...

, 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 illegally out under the Susquehanna River

Susquehanna River

The Susquehanna River is a river located in the northeastern United States. At long, it is the longest river on the American east coast that drains into the Atlantic Ocean, and with its watershed it is the 16th largest river in the United States, and the longest river in the continental United...

. Tunneling sharply upwards toward river bed without having drilled boreholes to gauge the rock thickness overhead, the miners came to a section with a thickness of about 6 feet (1.8 m) -- 35 feet (10.6 m) was considered the minimum for safety.