Detroit is gradually reverting back to a wild land. There is abundant vegetation and wildlife growing in the city itself, not out in the suburbs. At the link, you’ll see trees growing from buildings, wildlife in the city proper, it’s awesome.
Why is it awesome? Because “wild cities” are totally part of horrible dystopian hell-scape that is common in a lot of sci-fi. If this is coming, it means that a reversion to steam powered technology can’t be far behind, which means that my plans for an armored steam dirigible just might see the light of day.