As I have said a number of times before, I am not a proponent of "bunkers". I truly believe that many if not most people can prepare for reasonable natural disasters and man made ones, using the structures in which they live, and by making reasonable preparations, often with items located in the shops and stores you already use.
There are a few instances where bunkers or especially where tornado shelters can be necessary and beneficial. Homes and subdivisions where there are no basements, or homes in places like Kansas, Oklahoma and other states where tornadoes can be frequent and basements might not be, are places where sometimes families consider a buried structure in emergencies. I have a finished basement here at home, but for the purposes of research for this blog and for my daughter's home, I have been looking into storm structures, particularly those which are just underground.
In my research, I was most interested in the tornado structures which could be buried. Here is the e-mail I received from the president of the company above. It is my hope that this information, some of which is very interesting, will be helpful to you.
Letter from Mr. Webb: