If you're online, you've heard that a bridge over Interstate 35W collapsed last night. (As in the Dallas-Fort Worth metroplex, I-35 in the Twin Cities splits in two. I35-E goes through Saint Paul. I-35W goes through Minneapolis.)

On occasion, I've driven over that bridge, though much less than many people in the cities. A month ago I didn't notice any major problems, though I'm no structural engineer. There was some work being performed on the road surface (not the substructure), and to my layman's mind, a few jackhammers on a bridge carrying that much traffic can't cause a collapse like that.

What I have noticed, though is how quickly this tragedy has turned into an occasion for scoring political points. Go to the Democratic Underground. Go to some of the fever swamps in the blogosphere, and you'll find that the bridge collapse is the fault of the Iraq war, of tax cuts for the rich, the failure of the legislature to raise gas taxes, and contractors robbing the American people blind.

Excuse me if I say, simply, that's ... well, insert your own word. We don't know the cause, and won't know for months. Lack of funding? Crews were doing some work--again, minor--at the time. We've put in hundreds of millions of dollars for a choo-choo ("light rail") to ape Chicago and New York, and are planning to gut a vital part of Saint Paul to put in another one. Don't tell me there's a lack of funding for transportation.

Accidents happen. That's why we call them "accidents." Scientific research is built on probabilities. A 95 or 99 percent confidence level means that there's a 5 percent or 1 percent chance that what you're observing is ... chance. (I've taken graduate-level courses in statistics, so I know that I didn't phrase that properly. Still ....)