Interesting article on storm shelters.

I have helped put these together and they are nice. The biggest issues I have seen, if you put dirt on top and pack in the sides, the container roof and walls will fail. We used 2 inch Styrofoam on the sides and top of the container. The bottom rails of the container rested on concrete rails/ foundation on the ground. Keeps water at bay and gives you room for wire, plumbing and storage under the container. Cut through floor and have at it.. We then placed tires along the sides and fill with pea gravel and then added dirt. Keeps the sides from caving in. The roof was reinforced inside until the concrete dried. The re bar was welded to top outside rail. That way the weight go to the edges of the container and not on top of the container.
The best container I saw was a stainless steel unit with 4 inches of foam on the inside, easy to heat and keep cool.

I wish our water table was not so high, I would love to have one here.