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Anderson Cooper 360 Degrees

579-plus Killed, 2,500-plus Missing After Massive Flood Wave Hits Nepal-China Border; Survivor Of Devastating Flash Flood: "I'm Really Grateful;" Americans Rescued In Flood Speak Out; Rescuers Wary Of New Deluge As New Lake Forms Near Nepal Flood Zone. Aired 8-9p ET

Aired August 28, 2026 - 20:00   ET

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

BRIANNA KEILAR, CNN ANCHOR: We will see Elex's amazing story. Thank you for sharing that with us.

ELEX MICHAELSON, CNN ANCHOR AND CORRESPONDENT: Thank you.

KEILAR: And you'll hear much more from Anthony Hopkins on Elex's show, "The Story is" which is tonight at 9:00 Pacific and midnight here. Don't miss it.

And thank you so much for joining us tonight. AC 360 starts now.

[20:00:17]

JOHN BERMAN, CNN HOST: Rescues, reunions, remarkable survival stories, but also the sad reality they might be the exceptions, not the rule, in the wake of Nepal's increasingly deadly flood.

John Berman here in for Anderson, who is on his way to Nepal right now, and even as the death toll approaches 600 and the number of missing tops 2,500, we're getting fresh reminders of the deadly force that swept through a river valley.

What you're seeing there is a boulder, the size of a house, being pushed downstream, as though it were nothing. And we have pictures of a home with, as you can see, people trapped on a balcony as cars, trucks, enormous pieces of other homes and buildings just slam into it, and the river roars by.

(VIDEO CLIP PLAYS)

BERMAN: Just listen to that.

Two days later, the footage is utterly terrifying. Only now, we can also see what those waters have done. Nothing shows it better than satellite photos taken before and after the enormous wave of mud, glacier ice, and rubble came crashing through at speeds, averaging 120 miles an hour.

This is the video no one can forget of a border crossing being overrun. I want you to take a look at a satellite photo of how it looked before all of that happened. Now look at that, and now the imagery from after the flood. It is beyond chilling. There is no damage there to be seen because there's simply nothing

left to be seen. Every single structure that's visible on the photo on the left side of your screen is missing entirely from the one on the right.

It's a similar story elsewhere in the river valley, where we watched one bridge after another being swept away. Here's the valley from above. Three river crossings, there are visible. This actually video I think you're looking at right now is of a tunnel rescue there. This is the satellite image of above of that river valley.

Three river crossings there visible. Afterwards, the bridges are gone. Entire swaths of homes and buildings gone. Most of what was once a bend in the river also just gone, covered in mud. Again, with more than 2,500 men, women, and children unaccounted for.

As we have said, there have also been scenes of remarkable rescues: Nepalese soldiers crawling through thick mud toward a tunnel at a hydroelectric plant, where a number of people somehow survived, they were able to reach one of them, and he reaches them, looking dazed, covered in the mud that he himself crawled through.

We don't know how far he had to go. A soldier ultimately took his hand there, slowly pulled him forward, and then carefully handed him off to one of the older soldiers, who moved closer to solid ground and to safety. Just amazing to see that.

Elsewhere, a mother reunited with her son, one of two children she thought she would never see again. Both are safe tonight.

(BEGIN VIDEO CLIP)

UNIDENTIFIED FEMALE (through translator): I had completely lost hope that I no longer have my children. I was going through a period of grief, and I couldn't even control myself, and thought that there was no point in staying alive.

(END VIDEO CLIP)

BERMAN: There are other stories like hers. Thank goodness, even as far tougher facts come to life.

CNN's Hanako Montgomery spent some of the day on the ground in Nepal watching rescue choppers arrive.

(BEGIN VIDEOTAPE)

HANAKO MONTGOMERY, CNN INTERNATIONAL CORRESPONDENT: It looks as though people are getting off, holding some kind of luggage. We can't tell if these people are survivors or whether these are people of loved ones who are trying to find any remaining survivors.

Look, another helicopter up in the sky there.

MONTGOMERY (voice over): At this Nepali Army barracks in Trishali, helicopter after helicopter ferries people out of some of the hardest hit areas.

This survivor walked off showing no obvious signs of injury. He told us he'd spent days trapped on the mountain, convinced he'd die of hunger, waiting desperately for help.

UNIDENTIFIED MALE (through translator): There was no food or water with me. It was all swept away, and there was nothing I could do. I thought that my life was over, and that I would not be able to see my family again.

MONTGOMERY (voice over): Across the disaster zone, there are other extraordinary tales of survival. Rescuers pulled over a hundred people from tunnels inside a hydroelectric power plant in Rasuwa.

[20:05:10]

Some emerged so completely caked in mud it looked like a second skin.

But as the hours tick by, this rescue effort is now racing against time. The critical 72-hour window for finding survivors will soon run out. And here, outside the Army barracks, hope gives way to anguish.

With power lines down and communications cut, many families still have no way of knowing whether their loved ones are alive. So, they come here in search of answers.

MONTGOMERY (on camera): These are all relatives of people still missing and because they can't get in contact with them, they've come here to the Army barracks to give their contact information, their names, trying to see if the people that the Army are finding are the same people as their loved ones.

MONTGOMERY (voice over): After scanning this list with hundreds of names, there's little left to do but wait and cling to the hope that their families will soon make it home.

(END VIDEOTAPE)

BERMAN: And Hanako, you spoke with an Army general about these rescue efforts. What did he tell you?

MONTGOMERY: Yes, he told us that he'd never seen anything like this before. And that first 72 hours after the natural disaster is really a critical window to find survivors who are trapped alive. He told us that there are two main things hampering those rescue efforts. The first is, of course, that communication lines are down. It's been really difficult for survivors to get in touch with authorities and tell them that they need rescuing.

So right now, what they're doing is going from remote village to remote village, combing the area, trying to find anyone who might be trapped in the mud.

And the second thing he told us was the weather. Rain is forecasted for the next few days, and there's also news of a secondary flooding, potentially that could happen due to two newly formed lakes after that first initial landslide.

So again, John, lots of fears here about whether rescue efforts can continue, as they've done over the past couple of days, an all-out effort to find those remaining survivors, both Nepali nationals and of course, also foreign citizens, including Americans. Back to you, John.

BERMAN: The General told you he'd never seen anything like it. None of us has, period. Hanako Montgomery, thank you so much for your reporting over these last few days.

Professional photographer Stefano Lotumolo was on a bus when the flooding hit. This is some of the utter devastation that he and the people he was with just narrowly avoided. Others on that road behind them were not so fortunate, but he and his bus mates. They scrambled to higher ground where they found shelter in a small hut and waited out the night until military helicopters came the next morning. I was able to speak with him just before air time.

(BEGIN VIDEOTAPE)

BERMAN: Stefano, can you take me back to that day and tell me where you were when you knew that something was not right?

STEFANO LOTUMOLO, SURVIVED NEPAL FLASH FLOOD: We were just started, one hour and a half from the hotel we were staying the night, and we were almost reaching the immigration border. And just 30 meters in front of us all things were like we've seen the images where destroyed. And we've been lucky that our bus doesn't affect in the same time, the way it came.

We had like 30 seconds one minute to get out of the bus and to just start to climb the side of the mountain wasn't affected by the landslide and I think only two buses have been saved from that. And one was mine and all my group was safe. And I'm so grateful I can be here to, to tell the story.

BERMAN: Amazing, what were you thinking when you saw all that water coming at you?

LOTUMOLO: It's something that you're not really thinking something. You just hope you can be safe. You don't know if from other side the water can reach you because the we were very high, like 40 to 50 meters and the sound was unbelievable. Like we never, I never been in, in something like I was into an, I mean, you are in survival mode in that moment.

And I don't know, there is no word for explain. We just saw the buses, the people and the all the stuff 30 meters in front of us just took and go and we've been blessed completely.

BERMAN: What did it sound like? You said you've never heard anything like that before. Tell me about the sound.

[20:10:17]

LOTUMOLO: It was just, a big sound of death everywhere. And, yes, the only thing we try to do it is it was to be safe and nothing else. We've been lucky we didn't get into all the houses; all the villages being destroyed. There was nothing left in Timure.

And after the waves continue for kilometer. And there were a lot of workers. There were a lot of trucks, there were a lot of buses, but all has been gone and a lot of people died.

What we see -- the number we are listening are much more than, than what they are saying. Thousands and thousands of people have died.

BERMAN: Was anyone else on the bus able to escape?

LOTUMOLO: The bus in front of us and our bus, all the people were safe. All the other tourists we don't know.

BERMAN: Where did you go once you got off the bus? And how long was the water rushing past you?

LOTUMOLO: There was, maybe for 10 minutes, it continues to go down. And we went out of the bus and there were stairs next to us. And we start to climb the mountain. The water hasn't arrived because, in the other side of the mountain, the water reached and after came back and after start go down.

So, all the people, they get safe. They just climb the mountain side, it was safe and after we spent the whole day there and in the night time, it started to rain. So, the military couldn't reach us. And, we've been in a small house with all the survivor. And they were like, 50 to 60 people in a small house. We didn't sleep the night because it was continuing to rain. And, we were also worried about a little bit, but at the same point, I brought back food that night, it was the celebration of life.

And after in the morning, our prayer reached the right place and, the rain stopped. And from six, like when we went out in to the house, after one hour, the military start to came and they brought us in, in with the helicopter. And, in a couple of hours, all the people were saved and yes.

BERMAN: How can you make sense of it? How can you process it?

LOTUMOLO: Any time and I need time because, it's difficult to process. I'm grateful. I'm really grateful. And I've seen the death everywhere, but I'm alive and climate change is becoming stronger and stronger. We need to take care of our mother, the Earth.

BERMAN: Stefano Lotumolo, thank you for being with us. We're so glad that you made it. And we hope you get a chance to rest. I know this has been beyond comprehension.

LOTUMOLO: Yes, completely. I am thankful for you asked me to be there.

(END VIDEOTAPE)

BERMAN: From what sounded like death to a celebration of life. Just remarkable. We have more ahead tonight. We're going to hear from a doctor who is

looking for any word he can get about his mother and mother-in-law, both of whom are missing tonight.

And CNN's Will Ripley, speaking with an American couple who were caught in the disaster and are now sharing their remarkable story of survival.

(COMMERCIAL BREAK)

[20:19:12]

BERMAN: You're looking now at a search and rescue team in the Tibet region of China today, using ropes to pull someone across that raging water. It gives you a sense of the complicated mission that they continue to face.

Meanwhile, across the border in Nepal, two Americans are sharing their remarkable story of survival. They spoke with CNN's Will Ripley, who joins us now tonight.

Will, great to see you again. What did these Americans tell you?

WILL RIPLEY, CNN SENIOR INTERNATIONAL CORRESPONDENT: They are a couple from Northern California. John, named, Pattabi and Anjana they were at that border checkpoint between China and Nepal, the one that we now all know, the video of that black wave, basically covering up and destroying that entire building that looked to be about seven storeys tall.

They actually had been in that building. They had handed over their passports to officials in that building. And then they walked back to their tour bus, and they were there chatting with some other Italian tourists and other Americans as well, waiting for their paperwork to be processed. The Americans were part of a tour group that was one bus ahead of them.

[20:20:13]

That tour group was washed away when this happened, but because of where their bus was parked, when they saw from the hilltop above them this massive what they described as a black -- it looked almost like a black cloud of something moving towards them. They didn't know if it was water. They didn't know if it was a landslide. They had just a few seconds to basically run with the others on their bus up a hill, and they were able to watch what was unfolding from a safe place. Here's how they described that moment.

(BEGIN VIDEO CLIP)

ANJANA RAJA, SURVIVOR: So, the way it came, it came just like a Tsunami. It just came going all the way up and just like a tsunami, how it sweeps, going like a row, it just took the busses, the --

PATTABIRAMAN VENKATESARI, SURVIVOR: The houses. RAJA: Houses, people, everything. We saw people just getting sucked in

the water. It was so traumatizing to see that. People were screaming but of course, water doesn't hear anything. It just kind of suck them in. I don't know if they were thrown away somewhere in the shore, but then this happened, it was just a span of 30 minutes. In 30 minutes, everything was swept and gone. There was no water after that.

RIPLEY: How are you doing?

VENKATESARI: We are doing well. Just seeing so many people die. I think that's going to last for a while. It's going to linger for a while. I don't know if we will get over it any time soon. Just it was it was very disturbing. And the speed at which the things came down and it, you know, we were very fortunate.

(END VIDEO CLIP)

RIPLEY: There were moments when they were huddled together on a hill with about 70 people. They didn't know if they were going to survive. They had a cell signal for a brief period. They called their daughter, they said to take care of, told her to take care of her brother, and they gave her all the passwords on their accounts because they just didn't know if they were going to make it. And they wanted the children to be prepared to do what they needed to do.

They didn't really know they'd be safe, John, until the rescue helicopter came and took them back here to Kathmandu. They're going to be flying out back to the U.S. in the coming hours.

BERMAN: That is just remarkable. I'm sure their kids are just overjoyed to see them. And Will, I was speaking to a few hours ago when the list of the missing you were telling me had grown right before your eyes from something like 1,200, I can't remember if it was 1,700 to 1,800, but hundreds more missing being added to the list. What else are you hearing about rescues?

RIPLEY: Yes, that number of missing is now well over 2,000. And yet this list here, this handwritten list of just 31 people being treated here at this hospital for their injuries from the flood. This has stayed exactly the same. There have been people who have been sleeping out here overnight trying to get word about their loved ones. You can just see this wall of photos continues to grow, including young children on here.

There are also children whose photos are posted about five-minutes- walk from here over at the morgue. But they're children's bodies that officials are hoping people can come here and identify. So, it's just a horrible situation. We have been speaking with search and rescuers, including some who have come in from the United States. One complaint that they've had is that there's been a lot of bureaucratic red tape on the part of the Nepal government in terms of letting international assistance in.

They said they've come here. Teams from Korea, we spoke with teams from the U.S., teams from Europe. They wanted to help and they say that they were they were turned away and told to instead make donations to a larger disaster fund.

The Nepal prime minister is responding to some of that backlash, saying that that's a bit misleading. He says they are coordinating with China. They're coordinating with India and the problem is they learned this back in the 2015 earthquake, when a lot of international rescuers came in.

There were some difficulties with coordination with language. And so, they're having to sort those out. And they are grateful, they say, for the international assistance. But some of the people who've flown in to try to help have found themselves sort of sitting around wondering what they can do. And were nearing the end now of that 72-hour golden window, when the hope really starts to fade of finding people who may be trapped alive.

BERMAN: Yes, time is really of the essence here. Will Ripley, thank you so much for all of your reporting on this.

And as Will just alluded to, and as those photos in the wall there he was pointing to show for every survival story, there are many more stories like Dr. Dhruv Amin of long tense hours of waiting. His mother Meta, and we have a picture of her. I believe, there on the left. And his mother-in-law are both among the missing, along with a family friend who we also have images of.

They were in Nepal for a religious pilgrimage. Dr. Amin had also been before, but did not go this time and he joins us now.

Dr. Amin, thank you so much for joining us. I'm so sorry that it's under these circumstances. When was the last time that you heard from your mother?

DR. DHRUV AMIN, FAMILY MISSING IN NEPAL: Right before the night before. It's kind of amazing that their car actually broke down the night before. They would have crossed if their car had functioned and they actually stayed an extra day in Nepal. And the story is, is that because they were behind on their schedule for this pilgrimage, they went in early to try to cross to get out.

Our problem is that from our end, all we know is that they may have crossed the border at 8:13 from that building, and then we don't know anything else.

We don't know if, like the other story before there in that car that got swept away by the water, or did they get in the car and they drove and now they're on the Tibetan side and we have no idea what's going on.

In theory, they should be out of that area, but we have no idea. We have not heard from them. That's the frustrating part. Is that part of us are thinking that everything is great. And then the answer is that we have not heard from them in all this time, and we're just trying to reach out any way we can to hear something, maybe hear that great story that we heard from the previous survivors that we can relay back to you guys.

BERMAN: So, nothing, any assistance at all from officials in Nepal, anywhere?

I have not heard anything. I mean, the State Department has reached out. We have been reaching out in every sort of way that we can possibly do. Family, friends, anyone with any Nepalese connections, our tour guide, their tour guide has been very helpful. It's his son in law is with them right now and he has every incentive to work. But we've not heard anything since then. And the last location we have is on the friendship bridge, which is jarring for us that like that is the last known position that we have at all of all of them, including for my mother in laws phone.

BERMAN: And your mother has done this trip before, right?

AMIN: Yes, this is her seventh time I went in 2010, which was her second time. Things have gone much better. That's her in front of the building. That's me in front of the Friendship Bridge back in 2010. My mom, because she's done this so much, people feel that they can go with her. So, she's almost become like a tour guide where she will guide people. And she herself is like, we don't want to go but they don't feel comfortable going. And the scary and the sad part is it's not for this part that they're worried about. It's for the actual pilgrimage around like in Mount Over Lake and Mount Kailash when you're up in the altitude and how are you going to deal with this?

It's like, that's the part that were worried about, not necessarily the safest part of the passage, which is the border. This is the nice part of the trip. Afterwards, you're going up rough terrain, you have less amenities. The roads aren't great, and then you're going on a pilgrimage and you have to walk and like, this is the easy part. And I almost took it for granted. I'm like, okay, this is not anything worrisome. We'll worry in a couple days when you're actually on the "hard" part of the trip.

BERMAN: Dr. Amin, I can't imagine how difficult this wait is. I mean, I hear the pings going off there.

All I can say is I want you to check your phone, go check what those messages are, find out what you can. We send our best wishes to you and your family. I can only imagine how hard this is. Thank you very much and our thoughts are with you.

AMIN: Thank you guys, thank you guys, and I just hope that if anyone hears about this, we're just trying to reach out, hope that someone on the other side, because were not hearing anything, because we believe they're in the Tibetan side. Can you just get us some information so we know that they're okay.

BERMAN: Believe me, if we hear something, we will let you know. Thank you so much for being with U.S.

Next, someone who has lived and worked in the Himalayas for more than two decades on what the coming days might look like.

And later, the earth science behind the horror that started in just seconds and did so much damage in just minutes.

(COMMERCIAL BREAK)

[20:33:14]

BERMAN: Liquid, concrete, and impossible to outrun, that is how one scientist described the wall of rock, ice, and water you're seeing in this video right now. A glacier collapse caused the initial disaster. Nearly 600 people have been killed and at least 2,500 people are missing across Nepal and China.

With us now is Ben Ayers who is a journalist with Outside Magazine who has been based in Nepal for more than 20 years. He's a co-host of the "Everest Live" podcast. Ben, it's so good to see you. We see the number of people listed as missing growing, now 2,500. What's your sense of what the coming hours are going to look like?

BEN AYERS, JOURNALIST, OUTSIDE MAGAZINE: Well, as you mentioned in earlier programming, these coming hours are really critical in terms of the survivability of this disaster. I think in the coming hours, you know, night has fallen in Nepal. There are drone teams in the river corridor that are searching with thermal drones. They're actually hoping that the nighttime will give them an advantage to be able to see people by their heat signature.

I think in the coming hours, we're going to see, tomorrow morning, doubled down rescue efforts that we're -- as we're at the end of this critical window to try to, you know, get a hold of any remaining survivors. I heard some reports today that, like in this image we're seeing now, a number of people have been trapped that are hydropower workers.

A number of major hydropower projects were destroyed in this event and there are hundreds and hundreds of workers missing. About 900 hydropower workers are missing. I've heard reports that in one sort of mine shaft or in one tunnel, there are 200 workers still awaiting rescue.

BERMAN: Yes, one of the reasons the listed number of missing people rose by so much was because of all the hydropower workers. What are some of the biggest --

AYERS: Yes.

BERMAN: -- challenges facing and complications facing these rescue efforts?

[20:35:13]

AYERS: Oh, I mean, it's myriad. The challenges, you know, the -- probably the biggest challenge is that all of the infrastructure in the disaster zone was completely wiped out by the flood itself. There's no cell communication. There's no road infrastructure. There's no electricity for charging.

So it's been very difficult for the government to mobilize rescue efforts. Everyone has to go in and out via helicopter or via hours and hours walk on foot. Getting diesel to the heavy equipment that's needed to move some of these collapsed buildings is an incredibly difficult effort.

They've mobilized about 15,400 rescue workers currently and every single one of them needs to eat. They need to be taken care of and looked after. So it's an incredibly complex logistical challenge right now.

BERMAN: But how much do we know about what's happening on the Tibetan side of the border in China? So much of the information we're getting is from Nepal. That's where we have the video. That's where we think the conditions are worse. But what do we really know about the other side of the border?

AYERS: Well, when you look at the geography of the river itself, you know, the original glacial collapse happened within Nepal's border on the north side of this mountain called Langtang Lirung. That was right on the China-Tibet border. When that glacier collapsed, it hit the riverbed, briefly crossed into China, and then quickly returned into Nepal.

So the main damage to the Chinese side was in that border crossing that was mentioned earlier in the program. What we've heard from China is that rescue efforts are ongoing. But I think given the extent of the devastation in that point where the valley is so tight and there was such heavy destruction, I fear that the rescue efforts there are even more hampered than what you're seeing on the Nepal side.

BERMAN: Ben, listen, thank you so much for the insight you give us. Your years of experience really helps us understand what's happening on the ground there. Thank you very much.

Next, more --

AYERS: (INAUDIBLE). Thank you for the opportunity.

BERMAN: Appreciate it. More on concerns of fresh flooding after one and now two lakes began filling up behind the walls of rubble from that initial disaster. And a closer look at what might have caused this in the first place. Almost unimaginable natural forces at play and the warming climate that could make scenes like this more common.

(COMMERCIAL BREAK)

[20:41:51] BERMAN: We continue to bring you the latest in the devastating flooding in Nepal. And as we have been reporting, what is already a dangerous race to locate survivors has been further complicated by the risk of additional possible flash flooding and landslides. Operations were briefly paused this morning when a newly formed barrier lake began to overflow. And now a second lake has been observed in aerial footage of the flood zone.

We're going to CNN's Tom Foreman at the Magic Wall to help explain what we're seeing here. Tom, talk to us about the formation of these lakes so high up in the mountains.

TOM FOREMAN, CNN CORRESPONDENT: Yes, it is a real challenge here. Let's put ourselves into the map first. India down here, Nepal right through here, China up here, Mount Everest over this way, just in case you're wondering.

This is where this is all happening. If we move in to take a look at the area where that glacier collapse happened that you were talking about a short while ago, that's right over here. That gave way, sending all sorts of debris and mud and water rocketing down into this river valley here more than 100 miles an hour and creating all that havoc.

You want to see how much is involved there? All you have to do is go over here and look at this. We'll slide it over and you can see the damage. The before, this is the after. And in this after, John, that is where you can see the very thing we're talking about now, a lake that has formed right there and a lake that has formed right here.

Because as more water flows down and the debris is blocking its progress, those lakes have been building up there. And that is really the worry. The worry is that if all of the material blocking those lakes right now gives way, if that somehow breaks through in a catastrophic way, you could send another sort of pulse, a liquid shockwave right through the area that the rescue and recovery is being operated right now. John?

BERMAN: So what, if anything, can be done to alleviate the risk of those lakes just bursting?

FOREMAN: Well, one of the ideas would be, first of all, you monitor them to see if maybe they're draining at a slower rate. Maybe that helps off. Maybe they're a natural thing. Maybe not as much rain things that would help out a little bit.

I suppose in severe cases, they might see if there were some way to drain it off. But right now, what they're mainly doing is talking about trying to get some cameras and more sensors in place to see what's going to happen and telling the workers down below what they're telling them right now.

You have to be ready. Even amid all this dismal and dangerous work, you have to be ready to run for higher ground at a moment's notice if one of these lakes burst free. John?

BERMAN: All right, Tom Foreman, thank you so much. Just an important perspective on what's happening there and what they are facing.

With us now, Jeffrey Kargel, who is senior scientist at the Planetary Science Institute, and Glacier Specialist Dan McGrath, who's an associate professor in the Department of Geosciences at Colorado State University. And Jeff, for people who aren't scientists like me, can you explain just in basic terms what you think happened to initially cause this disaster?

JEFFREY KARGEL, SENIOR SCIENTIST, PLANETARY SCIENCE INSTITUTE: Yes. Thank you for having me on, and thank you for the excellent CNN coverage. Nepal and China are not alone in their suffering here.

[20:45:03]

Yes, what happened, we think, is that some of the bedrock high in the mountain, just below the summit of Langtang Lirung Peak, failed. It was fractured and it collapsed. And there was a small glacier resting on top. There still is part of the glacier remaining there.

And that piece of the glacier collapsed with the bedrock. And then on the way down, it -- just the frictional energy, we call it gravitational potential energy, turning into heat, which melted the ice. And so it was almost entirely melted by the time it reached the first really damaging point at the China-Nepal border.

And so, just horrific. I've never seen anything like this in my career to date in terms of Himalayan hazards and disasters.

BERMAN: And Dan, picking up on that point, you point out this is one of the most hazard-prone landscapes on the planet. I mean, how much ice are these glaciers losing every year?

DAN MCGRATH, GLACIOLOGIST: Absolutely. This, you know, is a major plate boundary where two continental plates crashing into each other over the last 50 million years, building the highest mountains on Earth. This has produced incredibly steep slopes and a tremendous amount of elevational relief from the valley bottoms to the tops of these mountains.

And there's a very large number of glaciers across high mountain Asia, something on the order of about 95,000. And cumulatively, that area is about the area of South Korea. And these glaciers are losing mass very rapidly.

If we take the amount of mass that's being lost every single year from these glaciers and that melt water and put it onto the island of Manhattan, it would inundate the island to over 1,200 feet. So we're looking at the top of the Empire State Building submerged in water every single year from glaciers across this region.

BERMAN: Wow. And we call it water, right? It would turn into liquid there, Jeff. But we've heard one scientist describe it as liquid concrete. This isn't, you know, like water that comes out of your faucet here. It's just this incredible destructive mass and impossible to outrun.

You said it was like the equivalent of at least 500,000 large dump truck loads of rock and ice at minimum. Talk to me about that, Jeff.

KARGEL: Yes, I think that is a minimum. In fact, the amount of mass that detached from the mountain top might not be all the mass of the flow that did all this destruction. Because as it flowed down, it picked up more rock debris. And once it reached the Bhote Koshi River, there was additional water that it could pick up.

And so, the final mass of this was even more than what detached from the mountain. But there is a question, have we identified all the entire source of water in this event? BERMAN: It really is interesting. There's still so many questions with something that in some ways is so photographed. We've seen so much video of the destruction, but we really still don't have perfect eyes on what happened at the very beginning.

You know, Dan, what would it have taken, if anything, to have seen this exact disaster coming?

MCGRATH: It's a very difficult thing to predict. In this region, we've seen a large number of glacial lakes form and grow through time and these are actively monitored and the most hazardous of these have been identified. But this is a totally different hazard.

This is not something, you know, when we think about the 95,000 glaciers across the region, we can't go out and monitor every single one of those with time-lapse cameras or other radar systems. And so, this is a real challenge.

And historical, you know, early warning systems, where we might have a stream gauge on a bridge to give warning, are not capable of providing sufficient warning, right? Those bridges were completely washed out during this event.

BERMAN: And Jeff, how dangerous are these ongoing rescue efforts? I mean, they did pause them for a time this morning. You know, given the composition of debris and the possibility of the lakes bursting, how dangerous would you say it is?

KARGEL: John, you just showed some information that I wasn't aware of until this show. That is the lake forming high up in the mountain.

[20:50:01]

This is extremely concerning because we already know that water perched up there would be an unstable mass. And, you know, there may have been some additional water that was unseen sort of hiding up there in the glacier, maybe not on the surface. And now we see a surface lake. You've got it highlighted in your box there.

And this is very worrisome, even more so than the landslide-dammed lake, because this is perched high up, and it could burst forth and flow into that landslide-dammed lake, and together they could burst out very, very rapidly. I do not want to be alarmist here, but the alarm bells are ringing, and the rescue crews have to be ready, like you said, to move to higher ground.

At every moment, they have to be thinking, like, if something happens, where exactly am I going to ascend the slope? Because running alongside the road ahead of the flood isn't going to do it.

BERMAN: Yes.

KARGEL: We just saw a video. You showed a video showing some people running along the road. And, you know, I don't know the details of that particular location, but in general, that's not the thing to do. You have to get -- BERMAN: No.

KARGEL: -- to higher ground.

BERMAN: Yes.

KARGEL: Not just a higher building.

BERMAN: This does not seem to be the type of disaster you can outrun.

Jeffrey Kargel, Dan McGrath, thank you so much for helping us understand some of the science behind this.

Up next, more on the possibility of a next time, whenever it might come. We're going to speak to an earth scientist working on the specific ways the region might become better prepared for future collapses like this and future possible flood disasters like this.

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[20:56:19]

BERMAN: We are still in the painfully early stages of the disaster in Nepal. At some point though, attention will turn to how this might be prevented, this type of thing prevented in the future, and the idea of a next time whenever it comes.

With us now is Alton Byers, he's a scientist at the University of Colorado's Institute of Arctic and Alpine Research and was planning to go to Nepal next month to help officials develop a glacier hazard management plan.

Thank you so much for being with us. Look, you were on your way for all intents and purposes to Nepal. I mean, how would the plans that you were making, the work that you were doing, address the catastrophe maybe of this scale?

ALTON BYERS, INSTITUTE OF ARCTIC AND ALPINE RESEARCH, UNIV. OF COLORADO AT BOULDER: Well, we're still going. We're leaving on the 13th of September. We're going to the Kanchenjunga Conservation Area in east Nepal. Kanchenjunga is the third highest mountain in the world.

And there, the -- there's a new program under development called the Sustainable Kanchenjunga Program. Now, this is being developed by the Management Council, by local non-profits, by local communities, and by donors in the U.K. And it consists of four or five different components related to sustainability, such as economic development, tourism development, biodiversity conservation, and glacier risk management and community preparedness.

And that's the one that they asked us to write a management plan for last December. And we're on our way over next month to begin the initial steps of implementing that plan.

BERMAN: People look at this disaster, and so many of us who've watched them before have said we've never seen anything like this. People on the ground are saying they've never experienced anything like this. Is there a way to tell what places might be particularly vulnerable?

BYERS: Yes, absolutely. And those -- we start with floodplains. In fact, that's the first activity that we do. We look at this in terms of what can we do immediately? What can we do in the next six months? And what can we do in the next two years?

So immediately, we can avoid, discourage the construction of new infrastructure in floodplains, OK? And a majority of the destruction you saw in these horrible videos are of buildings that were built in floodplains that had flooded in the past, either through glacial lake outburst floods or through monsoon flooding.

Now, at the same time, we need to start talking to local people and saying, concurrent with the research that's going to identify what are the most dangerous glacial lakes. We need to start thinking about a community-based preparedness plan. We need to start talking about things like early warning systems.

What's the most effective early warning system for here? Is it cell phone-based linked to a real-time camera up at the lake? Is it a more traditional laser water level monitor and sirens? What about zoning? We need to stop building.

What do we do with the tourist lodges that are already built below dangerous glacial lakes? And finally, what about that great big lake forming right now? It was beginning only two years ago, and recent satellite images show it's two or three times the size.

Can we get the Army to come in and do something now to lower that lake, as they often do during the monsoon with landslide-dammed rivers that back up the water? They'll come in and either with hand tools or dynamite, reduce the level there. So we have a lot. That's the community aspect, and then we have the scientific aspect that go hand in hand.

BERMAN: Listen, Alton Byers, thank you so much for explaining this. I know you are still headed there. The work even more urgent now. Thank you for sharing with us about these efforts.

And for information on how you all can help the Nepal flood victims, go to CNN.com/impact. That's CNN.com/impact. As I said, Anderson is on his way to Nepal right now. Please follow his coverage throughout the weekend and into next week.

The news continues. The Source starts right now.