"Pete C." wrote:

I considered building a combination pantry / safe room next to my
kitchen where I have space, however it would cost substantially more
than my cargo container design, and that is 100% DIY for either.

I wouldn't worry about it. Tornadoes cause about 80 deaths a year in the US.
There are 465,000 deaths from tobacco use, 365,000 deaths from poor diet and
inactivity, 85,000 from alcohol, 26,000 from motor vehicle accidents, 21,000
homicides, and 7,600 deaths from aspirin. There are 365 deaths a year from bath
tubs (drowning and falls). -- Doug