uwe seeger: just for the visitors. ic: and like thousands of men before me, i'm going down a coal mine. ♪ this is stepping into the bowels of modern german history. uwe: 1875, the shafts were built, and in the second world war they built the first tunnels in this. eric: okay. eric: coal from the ruhr valley, near the dutch border, helped build the steel that armed the third reich. ♪ eric: when germany lost the war and was split into a capitalist west and the soviet-run east, this coal helped remake west germany into an economic powerhouse. ♪ uwe: my grandpa did it like this: put it in the coal. [machine firing] coal, yeah, yeah, and we use it like this to destroy big stones. and this is just a short trip to the next tunnel. eric: i see why we need the helmets. eric: uwe seeger was born into this world, and thought he'd die in it. uwe: my grandfather was a miner, my father was a miner, my son was a miner for six years, but that's at an end because we don't have coal mining in germany. eric: you don't have black coal mine