This can be somewhat misleading for someone who isn't familiar with Detroit. When people say 'Detroit', they often mean the sprawling metropolitan area of the city of Detroit and the surrounding suburbs. The Detroit metro area has 4.4 million residents. The city of Detroit has only 700k. This article refers only to the city. And yes, the city has very few white residents. It is overwhelmingly poor and black.

It's not unusual, in the U.S., for urban centers to have a high minority concentration, but I believe this is much higher than most major cities.

Detroit is the extreme. http://en.wikipedia.org/wiki/List_of_U.S._cities_with_large_...