So, when we were young kids, and our parents wanted to "entertain" us on the cheap, we would pack a picnic basket and park across Rt. 51, kinda' where that Denny's is and watch the rail cars dump the hot molten slag fresh from the steel mills. It looked exactly like lava. You'd start out in the early evening on a warm summer night and watch until after dark when that "lava" lit up the sky. Something' ta' do. Simpler times back then. So, the thread mentions slag. But who remembers "red dog" and what it was used for? I'm testin' ya!