MICHELE NORRIS, host:
Tomorrow the government is expected to issue an interim report on why the levies in New Orleans failed during Hurricane Katrina.
As part of the investigation, today engineers got ready to recreate parts of Hurricane Katrina in miniature. It's all happening in a warehouse in Vicksburg, Mississippi, and NPR's David Kestenbaum paid a visit earlier this week.
DAVID KESTENBAUM reporting:
The warehouse is part of a lab run by the U.S. Army Corps of Engineers. Walk in an all of a sudden you're in New Orleans, and you feel like Godzilla because everything is just a few inches high. It's a model 50-times smaller than the real thing.
Mr. BILL SEABURG (ph) (Army Corps of Engineers): Yeah, it gives you a little perception if you could be the Jolly Green Giant or something. You know, we're probably 50-times, yeah, we're about 300 foot tall here.
KESTENBAUM: Bill Seaburg is a hydraulic engineer with the Army Corps. When I visited, engineers were getting ready to fill up the canals and the nearby lake with water. Today they created waves. Tomorrow, the waves will be the exact size and shape of some of the ones during the storm.
The Army Corps oversaw the actual levies, and now they're part of the official investigation into why they failed. Seaburg walks alongside the miniature canal, steps over a levy, and into Lake Pontchartrain. It's painted blue. He says the shape of the lake bottom and the canal and the surrounding coast is exact. They've had workers down on their knees, molding and checking it for about six weeks.
Mr. SEABURG: These are accurate to probably half a thousandths of a foot, .0005 of a foot.
KESTENBAUM: The goal of all this work is to help sort out why the Seventeenth Street Canal broke. The east side of the canal gave way, and water surged out, putting lawns, cars, houses, roads, and trees under water. The canal failed before water even got to the top of the walls. One theory is that the walls were built on a weak foundation. Here, investigators are looking at another possible cause: waves from the lake could have marched up the canal and put additional stress on the walls. Seaburg says the winds on the lake were over one hundred miles an hour.
Mr. SEABURG: The waves out on the lake there were fairly significant, on the order of ten feet. That's a significant wave. It will probably break, but then it'll reform and any time you have breaking waves, you have a lot of high velocities. So if we do have breaking waves in the canal here, then that could be a significant factor.
KESTENBAUM: The model is costing some $325 thousand dollars to build, and some observers say it's unlikely to uncover much.
Mr. BILLY PROCHASKA (Geotechnical engineer): I seriously doubt there was major wave action there.
KESTENBAUM: Billy Prochaska is a geotechnical engineer working with a separate investigation. It's funded by the state of Louisiana. He's seen video footage of another canal during the storm and says there weren't big waves. He says its pretty clear to him that the canal wall was built on a poor foundation and that it failed because of a bad design, a bad design that the Army Corps of Engineers approved.
Mr. PROCHASKA: I think they're just trying to cloud the issue here. They're trying to find a way out, that the walls were loaded, you know, in excess of what they were designed for.
KESTENBAUM: The Army Corps and other investigators working for the government say they are considering all possibilities. They're expected to release some of their findings in a report tomorrow.
David Kestenbaum, NPR News.