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CNN Live Saturday

Structural Engineers Discuss Investigation Into September 11 Attacks

Aired October 13, 2001 - 14:42   ET

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
LEON HARRIS, CNN ANCHOR: It's been just over a month since those deadly attacks at the World Trade Center complex and the Pentagon as well. Looking at what we have here now, live pictures you see there from Manhattan, rescue workers continuing to remove truck loads of debris from the site.

And investigations at the World Trade Center and the Pentagon are far from over, and for that purpose civil engineers are coming in and doing structural reviews of each of the buildings.

Joining us now from Houston, Texas are the team leaders from those projects. Gene Corley is with the Society of Civil Engineers and he is the team leader at the World Trade Center, and with him is Paul Mlakar. He is team leader at the Pentagon. Thank you gentlemen very much for your time today and for your expertise.

We're going to look at some pictures from those sites there at the World Trade Center and Pentagon, and I must tell you, I mean of course I'm not an expert as you are in these matters, but what is the first thing you think about when you walk into a scene like this and you look at a gigantic pile like that?

If you're an investigator trying to figure out exactly, I guess looking for some lessons from the structures here, what is the first thing you look at here Mr. Corley?

GENE CORLEY, CONSTRUCTION TECHNOLOGY LABS: Well, we have experience in looking at these things from previous examples. I was the leader of the team that did the investigation in Oklahoma City, so we have routines that we go through.

The first thing we do is collect the information about how the building was designed and then we start collecting information from the site itself.

HARRIS: All right and Mr. Mlakar, tell us about the site you're investigating. You're looking at what's happening there at the Pentagon. We know that structurally, we're not talking about the same kinds of buildings here, but would you go about the process the same way as you would with say 110-story building as we had at the World Trade Center versus a five-story building down at the Pentagon?

PAUL MLAKAR, ASCE TEAM LEADER, PENTAGON: Yes, indeed. The process is the same for both of the sites.

HARRIS: Beginning with what? What's the first thing you do?

MLAKAR: Well, the first thing we do is we figure out what the structural system was and how the loads were supposed to be carried.

HARRIS: And can you tell us what you've seen so far?

MLAKAR: Well, in the case of the Pentagon it is a reinforced concrete frame structure that supports the building. Much of that frame was damaged by the impact of the airplane, as I think the viewers can see in the pictures that are being shown.

HARRIS: Now, as I understand it, part of the Pentagon and it's kind of interesting because as an investigator you're going to get a chance to see, to learn quite more than you probably would because in this case, part of the structure that was damaged had actually gone through some renovations to actually make it more blast-proof, correct? And so, you get a chance to look at what you could have done better with the blast proofing versus the old structure itself, the original structure, correct?

MLAKAR: That's exactly right. That's exactly right, and we may learn that what we did worked as we expected it to work and, of course, that will be valuable to the engineering profession as well.

HARRIS: Can you give us any ideas or any tips from what you think you've seen so far, or anything you may have learned so far from looking at them?

MLAKAR: Well, of course we're just in the data collection phase and we really haven't fully analyzed everything yet. But, it looks like the reinforced concrete framing system at the Pentagon performed fairly well, but the investigation will look at that much more closely over the next few months.

HARRIS: Okay, let's go to Mr. Corley now and ask him pretty much the same question. From what you've been able to tackle so far, and from what you've been able to go over so far and the lessons learned that I guess we take to the actual reconstruction once that gets underway?

CORLEY: Well, yes. The Pentagon, what we find in our investigation, there may be some things that can be used in the construction of monumental buildings in the future.

Right at the moment we're, of course, in the early phases of collecting information and have not drawn any conclusions yet. We do though expect we will be able to make some recommendations when we're done.

HARRIS: All right, so you're just in the beginning phases, but have there been any surprises in any of the data that you've collected so far?

CORLEY: I'd say there are no surprises yet. We had a fairly good idea of what sort of data we would look for and what sort of things we would find, and I can't say that there's anything that's a surprise yet.

HARRIS: I have to ask you this question. This is really just a follow-through and a promise I made to someone else in an e-mail I've gotten from a viewer of ours who happens to be an engineer himself. He suggested that perhaps use of water-cooled beans could prevent something like this. What do you think about that?

CORLEY: Well, in this case there are a number of ways that fireproofing can be done and they all have their advantages and disadvantages. So, one of the things we will be looking at is what sorts of things were used, how they performed and what might be done differently in the future if we find that something else might have worked a little better.

HARRIS: Well gentlemen, how long will we have to wait before we get to see the reports that you all are compiling?

CORLEY: On the World Trade Center, we have a target date of about six months from now to finish our first report. Then, we expect there will be more detailed reports prepared later on.

HARRIS: Mr. Mlakar?

MLAKAR: And we're pretty much on the same timeline. We may be able to finish a little bit sooner, simply because the scale of the devastation, as bad as it is at the Pentagon, is somewhat less than at the World Trade Center.

HARRIS: Engineering team leaders Gene Corley and Paul Mlakar, thank you for very much for your time this morning and your insights, and you know that we will be waiting to see that report in the days and months to come. Good luck.

CORLEY: Thank you.

MLAKAR: Thank you.

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