This is a relatively new highway; I think the bridge is around 30 years old. There is construction underway on Highway 35. One hopes that didn't contribute to the disaster. This is certainly not an earthquake zone.
This is the kind of disaster that just doesn't happen in the United States--a bridge spontaneously collapsing, apparently, into a river. It is hard to convey to those who don't live here the astonishment of this sort of catastrophe happening on our most traveled highway.
As Mr. Klein notes, this kind of thing happens when local and state governments decide to cut taxes at the expense of critical services.
But more importantly, did John Hinderaker totally miss this recent incident? Perhaps this small event as well? Rick Perlstein, using this magic tool called "Google", found tons of examples of other bridges in need of repair.
But hey! No new taxes, right? Just don't complain when a sinkhole swallows your car.