Never being there but I remember folks talking about Detroit as it was ALREADY going downhill before the '08 Crash.
Detroit has been continuously and probably irreversibly declining since the 1950s -- the city's economy was almost entirely based on the auto industry, but the auto industry had started decentralizing and diversifying production locations away from the city in the 1930s. This was temporarily masked by the war economy of the WWII years, but once that came to an end, the economic troubles combined with long-simmering tensions over racial segregation in housing and schools.