I'm going to go out on a limb and say that that's probably ASB. New Orleans is the 6th biggest seaport in the United States. They're not about to just write off all those facilities, as that would require build a new seaport somewhere from from scratch.
God and the American Voter (further northward up along the Mississippi River Region) may have some to say about that...
One possibility is the Atchafalaya River becoming the new mouth of the Mississippi River. If the levees broke up there and the other flood control structures fail you would have all of the river going that way along with all the rains and such associated with Katrina.
http://en.wikipedia.org/wiki/Atchafalaya_River
IIRC, 60 Minutes did a story several years ago about how overdevelopment along the Mississippi River along its entire length from St. Louis to Louisiana, in the name of preventing ANY flooding, ANYWHERE on what is after all an enormous natural flood plain, had caused a "quickening" of the river, preventing any alleuvial soil settling in Louisiana and leaving the state to the tender mercies of the Atlantic Ocean
When the US Army Corps of Engineers built a series of dams on the Mississippi to do this, it was under protest, as they told congressional subcommittees: "If we do as you are ordering us, we'll be playing God with the natural course flow of the Mississippi, and we can't predict WHAT will happen..." Congress: "God works for the Congress, not the other way around!"
God: "Oh really?"
So, today, the Atchafalaya River has become the true mouth of the Mississippi River, and the story of the Amazing Disappearing State of Louisiana continues. On Dolby Sound [SIZE=-4]tm[/SIZE].
This is NOT a possibility. It is happening in real time RIGHT NOW. The US Army Corps of Engineers (post-Katrina IIRC) finally convinced Congress that God doesn't take His marching orders from them and got authorization for a series of dam demolitions along the Mississippi. Two. Big. Problems.
little problem: every idiot politician who is still fighting to protect "his dam" over everyone else's
BIG PROBLEM: God has apparently already made up His mind, as the project (with several dams blown already) seems to have failed. The New Mississippi seems to be just gouging its way around the blown dam sections and continuing to head ever more onto the New Man River even as we speak.