There's just no fixed process for dealing with the situation. Detroit doesn't necessarily want to assume responsibility, the residents don't necessarily want to become part of Detroit, etc. etc.

I think it is kind of a modern problem to think of government structure as a static thing. Like another example from Michigan, now that we have paved roads everywhere we should all but dissolve townships. Organizing most of what they do would work fine at the county level. There's some real neighbor stuff that they do, but they don't need to have zoning boards or road projects.