Here is a whole website of sadness. I spent hours looking through this fun explorers site seeing the decay of one of our industrial hubs. It’s a legitimate ghost town.
http://detroiturbex.com/index.html
It would seem to me that there is so much that could be reclaimed -- books, furniture, household goods, woodwork, stained glass -- that an enterprising individual or group could make a good living rescuing stuff from Detroit's ruins and shipping it off to other places.