Paul Krugman, writing in the New York Times, compares the decline of Detroit to another former American powerhouse, Pittsburgh. He looks at the job numbers, and suggests that Detroit’s failure is urban, as well as industrial.

In that sense, Detroit’s disaster isn’t just about industrial decline; it’s about urban decline, which isn’t the same thing. If you like, sprawl killed Detroit, by depriving it of the kind of environment that could incubate new sources of prosperity.

The centre of Christchurch was declining, even before the quakes. Seismicity simply sped that process up. While we may not have been an industrial powerhouse, there is still a lesson for us here: we need to kill the urban sprawl, before the urban sprawl kills us.