While steel mills are eminately modellable - there is, to my mind, nothing more depressing than a steel mill that is not operating. As a kid, 1952-55 Dad was headquartered in Pittsburgh, we would routinely travel back to Baltimore to visit family using various B&O trains as the means of transportation. Most frequently we would leave Pittsburgh on #10 in the neighborhood of 10 PM and get to watch the light show being put on by the steel mills between the P&LE station in Pittsburgh and McKeesport. Our return was frequently on #9 that would arrive Pittsburgh in the 8:30 PM range and would get the light show inbound from McKeesport. Laser light shows have nothing on the shows that steel mills produced. As an adult I have experienced driving past a number of out of operation steel mills - Steelton, the various mills around Youngstown, Sparrows Point - at best depressing in some cases no longer able to see that a steel mill ever existed on the property. The former Beth Steel property at Sparrows Point is no longer known under that name, now it is Tradepoint Atlantic and is being developed into a number of businesses.
Sloss Furnaces, Birmingham, AL is now a National Historical Landmark. I watched it go from a derelict two-furnace junk heap to a commendable site in the 30+ years I passed on ATK Crescent.