Namek69 A door covered in pen graffiti. Similar Images ...based on the tags: doors, fire-escapes, graffiti, signs... Watching the sun set behind downtown Detroit is my favorite memory from the building. Ultimately, it was the bad roof that doomed these buildings. The working end of the blast furnace, where molten metal would flow like lava out of the furnace… a process called ‘tapping’. The left cave is the largest of the three, and shows the most evidence of expansion. Old boathouses near the dock. This heavy door opens directly into the missile vault and was used to load and unload the missile erector. A typical narrow hallway at Birtle. The bottom of the elevator in the new foundry. Looking out of the brewhouse toward the river.