Detroit was hit very hard by the 2008 real estate collapse. Here's a blog showing pictures before and after. You can see a stretch of houses that were occupied and doing fine in say 2006 and just a bare stretch of ground five years later.
The city of Detroit was in a financial crisis back to at least 2004. I believe that it was the 2004 Census that put the city below 1M people, which lost them a lot of Federal dollars.
http://goobingdetroit.tumblr.com/