Lukens Steel Mill in Coatesville, PA was one of the largest rolling mills in the world at peak operation. The part of the mill we toured closed in the 1980s, but was the site of the site's most notable work - the structural steel "trees" from the World Trade Center. Because of the worker's ability to make high quality thick steel plate, Lukens also completed many military contracts, including aircraft carriers, subs including the USS Nautilus, and battle tanks.