Comparing this to 9/11 - 9/11 didn't disrupt the basic infrastructure structure of the economy much in the long run (ignoring the tragic personal toll for a moment). Of course the short term effects were substantial.

Katrina marks a permanent change in the infrastructure of the economy, plus an outright destruction of energy resources that may take a long time to replace. It's effects on the economy will be greater than 9/11.

There is a recession on now, mostly caused by the sudden reduction of total energy availability - plus the loss of a million jobs. Those main stream economists that think we just bounce back from this, like a rubber ball, are plain silly. The tremendous amount of resources that will be diverted to rebuilding are not available from either domestic or foreign savings. Net national savings is less than zero, and foreigners already provide nearly $900 billion per year to the US (also called the current account deficit).  That means the rebuilding of the Gulf will create a capital shortage - regardless if interest rates go up or down from this point. Actually, this is a recession that may cause interest rates to rise, maybe much higher, at the same time total energy costs deliver a crushing blow to disposable income.

Depression anyone?