It's amazing that we never really worried about bridges before but we're sure worried about them now. Now we pray we get to the other side. We knew the Longfellow was getting a little long in the tooth, but looking at the rust on those skimpy supports holding it up, well, I'm not so sure I'd want to be riding the Red Line between Kendall and Charles every day. I suppose that the good news is that we tore down the Central Artery before it collapsed on our heads!

But what happened in Minneapolis was a fluke. It was a tragedy but it was also random. Every time we cross a bridge or step into an elevator or ride in a plane, train or automobile, we trust our lives to engineering. Mostly things work out OK. There are more than a half million highway bridges (of which, 75,871 are deemed structurally deficient) in the US. One fell down.

If there's a lesson in the bridge disaster it isn't that we should panic, it's that ongoing maintenance and an investment in infrastructure should be a nagging priority when drawing up budgets. Especially when the bridge panic of 07 fades from the collective memory.