I see it like this. A lot of predators in the neighborhoods of Detroit. After 2 or 3 decades of middle class flight its slim pickings for these criminals. You don't want to be assumed to have ANYTHING. Back in the 80s and 90s you could be victimized sure, and many people with things to lose and steady income beat it on down the road. 2012 the target class is a lot more narrow.
Order of operations = Steal their valuables, chase them out the neighborhood -> strip the plumbing.