TORNADO THOUGHTS from reader Felix Kasza:

I just do not get it. For how long have Americans known about Tornado Alley? For how long have they known that a typical house would not withstand a once-in-20-years tornado, much less a worse one?

And yet houses are still built of clapboard and a couple of two-by-fours. Just like New Orleans is being rebuilt just where it used to be, because that worked out so well the first time around. (I except the French, which were uncharacteristically smart and built on the only hill there.)

Bricks, stones, mortar, concrete, steel. When will America learn about building for inclement weather?

Well, it’s not as simple as that. Even in Tornado Alley, the likelihood that any particular house will ever be hit by a tornado in its lifetime is pretty low. (Also, brick and stone construction, while good for tornadoes, is bad for earthquakes; wood-frame buildings actually do better there.) And basically nothing except quasi-fortified structures will withstand an EF4 or EF5 tornado. Those are very expensive, and people don’t want to live in bunkers.

That said, relatively minor additions (e.g., hurricane anchors for roofs, shatterproof glass for windows) can make a big difference for less apolcalyptic conditions.