32VAC, almost no homes are "timber" construction. Rather, they are "stick" or "balloon" frame .... light wood members, with gypsum board facing.
This method was developed so that lots of homes could be built fast, cheap, with minimally skilled workers. It has far surpassed expectations, and continues to be the method of choice.
Even where you see a brick home, the brick is usually just a thin veneer.
Storm shelters are not required, nor are they often designed into the home.
"Tornado Alley" sounds like a limited route, but the description actually applies to an area at least half as large as Australia.
As flimsy as this construction may sound ... and as dramatic as the pictures appear ... the USA actually has far fewer casualties from natural disasters than similar events elsewhere. Where a similar storm just a few miles off our borders will claim hundreds of lives, we lose only a few .... and suffer much less secondary loss (fires, disease, etc) as well.
