late but adding to this, some places in the tornado-prone South
can't have basements or underground shelters. Florida is a swamp, for example. On other places, there are public above ground concrete shelters that are reinforced with steel that can handle tornadic winds. Can't really confirm and no idea if the huge public ones work (one area in the South I visit built a public shelter
after it got hit by a bad one), though I do hear of small tornado shelters brought for houses get by unscratched while the family house is unfortunately blown to pieces.
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