With all the concrete and security systems, a Supermax is probably the best place to be

Not to mention if someone were to bring in the infection there's no avoiding it in prison.

Pretty much what happened in The Stand. Imagine having to ration toilet bowl water while everyone in cells around you goes insane from lack of food and water.

Costco, BJ's and Sam's Club are probably among the worst places to be at the outset of the outbreak. Weather you are there, or attempt to go there.

Wait until it all blows over... a couple days or so, then venture out. Even then, stay away from the shopping clubs and Wal-Mart. Go to one of their distribution centers instead. It will be a whole lot less likely you'll run into survivors and the place won't be ransacked by the looting.