see the carnge in detroit , page-16

Not in the 1950's. Then it was THE most desirable city in the US.

Cities always thrive on growth. More and more money for more and more infrastructure. No growth is bad, as the maintenance issue comes home to roost and can't be hidden behind capital spending programmes. Declining population is death as there is insufficient money for maintenance. It's amazing it lasted as long as it did - purely on borrowed money, as we now see.