Turkish government officials estimate that ten thousand victims remain trapped in the debris left behind by Tuesday's massive earthquake. Margaret Warner leads a discussion on the rescue efforts.

MARGARET WARNER: And for more on the earthquake and its aftermath we turn to Baki Ilkim, Turkey's Ambassador to the United States; Tim McCully, international services manager for the American Red Cross, which is taking a lead role in the rescue and relief efforts in Turkey; and Robert Wesson, a research geophysicist at the U.S. Geological Survey.

Mr. Ambassador, first, our condolences, this terrible tragedy. I understand you were there at the time it hit.

BAKI ILKIM, Ambassador, Turkey: Thank you very much. I was in Istanbul when the earthquake took place. I was staying in a flat in the center of the city. There were first noises. I realized that it was an earthquake. I woke up. The whole flat was shaking. And I thought to leave the place immediately. I went down and I found out the other neighbors all had gone down, so we all spent the night outside. The reason for it was that secondary tremors continued throughout the night, and the inhabitants were advised to leave their premise. Also, at that stage electricity and gas was deliberately cut off to prevent fire and also explosions. But as much as I could see in Istanbul, since it's not the epicenter, the damage is relatively limited when compared to the damage that you witness in certain other areas. And I have to underline that it is about 100 miles, the epicenter is about 100 miles East of Istanbul. So it's not Istanbul, itself.

MARGARET WARNER: Now, the official figures so far are 3800 dead. How many from reports that you have from your government do you expect or fear? How high do you think that's going to go?

BAKI ILKIM: That would be a speculation. The official reports that I have as of tonight was that 3,839 citizens have lost their lives, and 18,000 are injured. My prayers are that I hope that we don't have many more victims.

MARGARET WARNER: Are you as overwhelmed in terms of the rescue and relief efforts as those ITN reports suggested with aid -- not even -- help not even getting to a lot of these areas?

BAKI ILKIM: No. I don't know you know. I can't comment about the commentator in the reports, but definitely everyone is doing their utmost. And the area is not that small. The number of collapsed houses are quite many, and we are over-stretched. As of today we received about 1,400 technicians who are involved in the search and rescue operations. So the authorities are doing their best. In the report, it also, in one of the reports, the people were thanking the army for saving someone, so everyone is trying to do their best, but it's limited, the resources are limited.

MARGARET WARNER: Tim McCully, from what you're hearing from your people on the ground, how much progress is the rescue effort making, and give us also a sense of just the enormity of this.

TIM McCULLY, American Red Cross: I think as you saw from the footage, this is a terrible tragedy. This is a disaster of very large proportions and like you, our heart goes out to the people. The Red Cross is active; it has been active since moments after the earthquake. The Turkish Red Crescent Society, assisted by the entire Red Cross and Red Crescent movement, has rushed all possible supplies to the region. And we are beginning to make headway.

MARGARET WARNER: What are the biggest difficulties you face? I mean it looks all very difficult, I know, but give us a sense of what's involved.

TIM McCULLY: In the first two to three days, the most difficult obstacle to overcome is the need for search-and-rescue teams to find wounded people and to get people out of the damaged buildings. But I think it's also important to recognize that this is a disaster that will take some time to recover from. And part of what the Red Cross is trying to do is also make sure that there are enough food stocks, shelter, tents, medicines and field hospitals in the affected regions so that people can begin to recover. And I want to stress that this is being done on a coordinated basis with the Turkish Red Crescent, all Turkish authorities and a range of other humanitarian organizations.

MARGARET WARNER: All right. Rob Wesson, give us an explanation for why this occurred.

ROBERT WESSON, U.S. Geological Survey: Margaret, this earthquake that occurred yesterday is one of a sequence of many earthquakes which have occurred and will continue to occur along the North Anatolian Fault. In essence, this fault is one of the boundaries of this mosaic of plates that make up the Earth's surface. The mass of Turkey is moving westward relative to Eurasia and the Black Sea. And this movement occurs along the North Anatolian Fault. The movement over the geologic era is about the same rate as the San Andreas Fault; that is, it moves about one inch a year on average. But unfortunately, it doesn't occur smoothly. It occurs in jerks, like this earthquake we experienced yesterday.

MARGARET WARNER: And how does the earthquake in Turkey compare in magnitude, say, to earthquakes that Americans might be familiar with?

ROBERT WESSON: The earthquake that occurred yesterday, after all the data is in, is about a magnitude 7.4. This makes the earthquake larger than the earthquakes that shook San Francisco in 1989 and Northridge, in the Los Angeles area, in 1984. It's a little bit smaller than the 1906 earthquake in -- along the San Andreas Fault in San Francisco.

MARGARET WARNER: And what kind of -- and this might be not quite in your are, but what kind of devastation and death tolls can one expect, or should one expect from a quake of that magnitude?

ROBERT WESSON: The dominant factor in deaths and casualties in earthquakes in the end comes down to the construction and the type of buildings the people live in. In California and in the United States, particularly in California and in the Western United States, we have a very strong building code. Engineers have worked hard to make that building code better so that our buildings are constructed to resist, when at all possible, damage, and particularly collapse, from earthquakes of this size. We also work hard at enforcing that code. The contractors have to get their plans inspected and then inspectors go actually into the field to the construction sites to assure that the buildings are being constructed to the standards to which they were designed.

MARGARET WARNER: Okay. So Tim McCully, would you agree from your experience, that there is a direct correlation here between the kind of devastation that you all come in to take care of and the degree to which construction has been -- this has been anticipated?

TIM McCULLY: Yes, I think clearly one can talk about varying construction codes and their ability to stand up to an earthquake. But I think from our perspective that's not what's important right now. What's important right now is speeding the people, the money and the relief supplies in to save people's lives and help them get their lives back together.

MARGARET WARNER: Mr. Ambassador, there have been editorials, as you know, in the Turkish press already today talking about the poor construction. I mean would you agree that that's part of the problem here?

BAKI ILKIN: Well, there might be -- there could be and probably there are some substandard constructions. So that is something that the authorities will have to look into it and see what went wrong. But in addition to that, as you must have seen, the magnitude of the earthquake is such that you can build bunkers, but then you have to find an optimal arrangement, the cost factor and the safety factor. So we may have to tilt more towards safety from now on. But as I said, you cannot only attribute what has gone wrong to poor construction.

MARGARET WARNER: And of course that's a lot more expensive, the kind of codes that Rob Wesson's talking about in California, that kind of building's very expensive.

BAKI ILKIN: And then also the duration of the earthquake I believe is also important. It was 45 seconds.

MARGARET WARNER: All right, Rob Wesson, give us a sense now of what we can expect in terms of -- we hear a lot about aftershocks. Are they inevitable? How soon can one expect them?

ROBERT WESSON: Aftershocks are almost ubiquitous phenomena following a large earthquake like this. Typically the rate or the number of earthquakes or aftershocks per day declines through time, but not necessarily the magnitude of the aftershocks. So from an earthquake of this size, one could -- as I understand, there have only been aftershocks of magnitude 5 or so to date. There could be earthquakes -- aftershocks as large as that or possibly as large as magnitude 6. We don't know that. There's nothing -- nobody can predict when such aftershocks might occur, but it has to be a concern both to the people and to relief workers and anyone who's around these damaged structures.

MARGARET WARNER: All right. And tell us how that complicates relief efforts, say, for an earthquake as opposed to say a hurricane, which is a one-time event.

TIM McCULLY: I think that in an earthquake disaster, you have to look at the relief operation in a series of phases. And the ambassador and I were talking about this. In the first few days, the most important element is to get the search-and-rescue teams in there to extinguish the fires that are caused by the earthquake and to deal with the emergency medical needs of those people that are wounded. Once that emergency phase passes and you have reasonable measures that you've take to ensure you've gotten the wounded out from the damaged buildings, then you begin the process of looking at longer term healthcare. We do run the risk of severe public health issues that the Red Cross and other groups are beginning to take into account. Field hospitals are being set up to provide a range of different medicines. You also have to take into account that many of these buildings, particularly in the outlying areas outside the major urban areas, have not yet been visited. And those are the ones that the relief community has got to be able to get access to and address the issue of shelter, tents, blankets and perhaps more sustainable long-term housing has got to be a priority for the relief community.

MARGARET WARNER: And how soon do you think you can get to these outlying areas, either one of you?

TIM McCULLY: We are getting there now.

BAKI ILKIN: As quickly as possible.

TIM McCULLY: I do know that the Turkish military and the Turkish Red Crescent have already started delivering tents to some of these outlying areas. The International Red Cross has just issued an appeal for almost $8 million today, and a good chunk of that money will be used to provide emergency shelter and food not just in the major areas but to the outlying areas as a whole.

MARGARET WARNER: How much more do you need from the international community?

BAKI ILKIN: As much as possible. It's not the first time that we are suffering from an earthquake major earthquake. We have been able to dress the wounds in the past. The government is doing its utmost to do the same again, but the more assistance we have, the better it is, and -

MARGARET WARNER: But, I mean, give us some sense. You said 1,400 technicians have come in. Is that a drop in the bucket, is that half what you need? Do you have any --

BAKI ILKIN: I wouldn't be able to give you any exact figures at this stage because as you have, I've been following things from a certain distance. But I can tell you it's three track: Track one, and the most important one is to get people under the rubble as soon as possible because there's a deadline. I don't know how long it is, but there is a deadline. So that's track one. Track two is to put off the fire in Izmit, because that's -

MARGARET WARNER: At the refinery?

BAKI ILKIN: Then feed and shelter the ones who are outside. And as you have heard, they have to stay outside because they fear that there may be a new wave of earthquakes. So these are the imminent problems that we have to deal with.

MARGARET WARNER: All right. And if individual Americans want to help, Mr. McCully, what can they do?

TIM McCULLY: Right now, the best way for people to help is to provide cash. Cash is the fastest way for us to get people, relief commodities, food and medicines to the scene. And groups like the Red Cross are taking donations. The Red Cross has set up a 1-800 toll free number. That number is 1-800-HELP NOW, and we are taking cash donations, and we are guaranteeing that those will be used for the victims.

MARGARET WARNER: All right. Well, thank you all three very much.

ROBERT WESSON: Thank you.

TIM McCULLY: Thank you.

MARGARET WARNER: And our good wishes.

BAKI ILKIN: Thank you very much.