I wouldn't wish that upon any of my Customers, and there have been close calls in at least five states.  Two weeks after this picture was taken the gentleman told me they felt secure as a tornado came to within a half mile of their Arkansas home.  When it does happen, the shelter will stand straight and tall through it all.  In one tornado alone there were 16 various above-ground shelters that all did their job, and none of them were constructed of 3/8" thick cylindrical steel!