It was sad to drive past shuttered factories and abandoned automobile assembly plants...vast parking lots covering tens of acres...empty except for the occasional security car (who wanted to know why I was taking photos and of course wouldn't let me in for a closer peek). It was even sadder to drive past block after residential block of boarded-up, abandoned or burned out homes. According to some reports, entire neighborhoods have disappeared and become devoid of homes.
http://www.burnedoutdetroit.net/about/ and http://en.wikipedia.org/wiki/Devil's_Night.
Also, Detroit fell victim to a number of other inner city issues such as urban flight where many fled to outlying suburbs, leaving empty homes behind...which became targets for vandalism, squatters and arson. The reasons for leaving of course, are legion. Allegations of corruption in city government offices and racial tensions are among the ingredients of the soup of recession that bubbles throughout the city.