It's not just the decline of the auto industry, which by itself can be attributed to poor upper management and union abuse.
But, in reality, Detroit is America's poster child for the disastrous federal welfare policies that have gutted the black family and made inner cities everywhere unlivable.
From The Detroit News: http://detnews.com/article/20110323/MIVIEW/103230338/Census--Exit-the-Detroit-black-middle-class#ixzz1HT0JbX4U
It is sad to see what happened to a once beautiful, bustling city. I first came to Detroit in 1969, when the city was still alive and business was booming. If Mayor Bing can turn things around, along with the new Governor Snyder, that will be a miracle.