[steveegg]

good point. 10 backpack bombers walking up to these levees and blowing 10 holes in them, could have done this to New Orleans at any time.

It would take more than backpack bombs, but not much.

[Strategerist]

It would take a lot more. It would have to be a full size OKC-style truck bomb or larger.

Any personally portable bomb wouldn't even affect a levee at all.