I used to live in Macon, Georgia, which is majority-black and "collapsed" in the '80s for the same reason as Detroit: the economy changed and the well-paying factory jobs disappeared or moved. There was a shitload of white flight there too, but most of them only went as far as the surrounding county. A ring of all-white suburbs sprang up around Mcaon. Still utterly dependent on the city for jobs, services, shopping, etc., those suburban residents did nothing but bitch and moan all day long about how Macon was dangerous and awful because of "the blacks," which is the politest way they put it.
I lived downtown for four years. Never a bit of trouble. It was a perfectly nice place, and doing its best to rebuild. But the old white bigots, who also announce they never go downtown, are still whining about how bad it is.