Being here in the middle of the country & so far from the ocean the lost at sea, hurricane, tsunami, etc. aren't on the list.

A major terriorist attack that affects the food supply chain is #1 for me. And if you're aiming for that one you will by default cover most other areas as Susan has already pointed out.

One downside with a major earthquake is that all my supplies are in our storage area & if our house collasped & burned we would be hurting until I could get resupplied.

I think everyone is susceptible to an earthquake. Keep in mind that the New Madrid Earthquake of 1811 rang the church bells in Boston. Just because you haven't experienced one in your lifetime doesn't mean...