Your right about tornadoes being unpredictable. I was thinking more along the lines of people going to the shelters long before the tornadoes dropped from the sky. It would be claustrophobic. What I hear from alot of people is cost and no place to bury one. With field lines and septic tanks in the backyard, if you don't have much land what do you do? I don't have any real answers I'm just throwing things out there because I'm in the same boat they are. Thanks for your input.