We're not in a position to go through a tropical storm without reflooding a lot of areas that were just drained.

We'll run two or three simulations at the same time, but we have difficulty shifting output around -- the files that come out are huge. Let's say you want to get them over to someone in Lafayette or Lake Charles and have them do an analysis while we do something else.

It has been known for a long time that New Orleans was not adequately protected from the worst storms.

There are some disasters beyond comprehension, and I think this is one of them.

We are treating this as murder, and are appealing for anyone with any information to contact our incident room which has been set up at Fairwater police station, on 029 20 571 530.

We have been warning about these things for a long time and haven't gotten far. We were predicting overtopping of the levees on Saturday. If you look at some of those animations on our Web site, it's pretty chilling.

That's what modeling does, it makes something real before it happens.

What do you do when the city floods?

This should not have been a big deal for these floodwalls. It should have been a modest challenge. There's no way this should have exceeded the capacity.