Blast furnaces P1-P6 at Jones & Laughlin’s Pittsburgh Northside Works in the 1950ies.
The furnaces were closed down in 1979 and demolished in 1983.
Jones & Laughlin became LTV Steel in 1984 which became ISG in 2002 which became Mittal Steel in 2005 to become part of ArcelorMittal in 2006.