60 Minutes - 03/29/2026: Inside the Tower, Unmanned, Wonder of the World

Episode Date: March 30, 2026

Long lines at the airport and a runway crash this week have been a reminder of how the country’s busiest airports are stretched thin. It all comes a year after a collision between American Airlines flight 5342 and an Army helicopter near Washington, D.C. marked the deadliest aviation disaster in almost a quarter century. Correspondent Sharyn Alfonsi speaks with an air traffic controller inside the tower on the day of the collision and reports on what went wrong and what needs to change. How has Ukraine been able to level the battlefield in the war against Russia? By using remotely controlled and unmanned drones, including on land and sea, against the invading Russian troops. CBS News’ Holly Williams reports the U.S. military is now learning from Ukraine's innovative, battle-tested drone expertise.  60 MINUTES explores an epic underworld of caverns the size of skyscrapers, known as Hang Son Doong in Vietnam, over a multi-day expedition. The journey reveals a colossal subterranean world: rivers, limestone rock, dense jungle and an underground lake. Correspondent Scott Pelley speaks with the cavers who discovered and surveyed the cave in 2009. To learn more about listener data and our privacy practices visit: https://www.audacyinc.com/privacy-policy Learn more about your ad choices. Visit https://podcastchoices.com/adchoices

Whether it's with your besties or date night, get to all the hottest concerts with GoTransit. Go connects to all the biggest entertainment venues and makes it affordable with special e-ticket fares. A weekend pass offers unlimited travel across the network on any weekend day or holiday for just $10. A weekday group pass offers the same weekday travel flexibility, from $30 for two people, up to $60 for five.

So no matter what day of the week, Go's got you covered. Find out more at goadransit.com slash tickets. Last year's collision of a passenger jet and army helicopter in Washington, D.C., killed 67 people. For the first time, you will hear from an air traffic controller who worked inside the tower. Was there pressure to get more planes in and out? And what we discovered about continuing problems at that airport. Why do we always have to wait until people die to take action?

Forget everything you think you know about. warfare. The traditional front line in Ukraine has expanded to a 10 mile wide swath, where anyone spotted by a drone, can be hunted down. Tonight, lessons from Ukraine's kill zone. Necessities de Mazr of invention. Excellent, Scott. That's really good. Nothing could prepare us for the majesty of the largest cave passage on Earth. Skyscraperers, would fit in here. A 747 could fly through. Maybe most remarkable, all of this was discovered only recently. And there aren't a lot of places on earth that you can discover for the very first time. No, you have to look pretty hard for them.

I'm Leslie Stahl. I'm Bill Whitaker. I'm Anderson Cooper. I'm Sharon Alphonsey. I'm John Worthy. I'm Cecilia Vega. I'm Scott Pelly. Those stories and In our last minute, a Final Four legend has a game plan for America. Coach Mike Shoshesky. Tonight on 60 Minutes. It was a week of chaos at airports across the country. Gridlock in Washington left TSA workers without pay, triggering four-hour security lines in some of the nation's busiest airports.

Last Sunday, a commercial jet crashed into a fire truck while landing on a runway at New York's LaGuardia airport. Dozens were injured and two pilots were killed. Authorities are investigating, but the air traffic controller on duty said they were dealing with an earlier emergency, and soon after the accident said, I messed up. It is a chilling reminder of just how thin our aviation system is stretched.

Last year, American Airlines Flight 5342 and an army helicopter collided over the point. Potomac River near D.C., the deadliest aviation disaster in almost a quarter century. Tonight, you will hear from an air traffic controller who was inside the tower the day of that collision. She tells us why controllers at Washington's busiest airport have been warning of danger for years. It is a story of a system pushed to the breaking point, and the shattered families left to pick up the pieces. In southern Maryland, seven widows, who whose husbands were on flight 5342 agreed to share their story together for the first time.

The men, all work buddies, met up with friends in Kansas for a week of duck hunting. The women shared these photos with us and the excitement their husbands felt leading up to the trip. Alex got home from work, he was like, before you say anything, it's already paid for. I was like, when do you leave? There was no asking any more questions. He was so excited to go. like it literally looked like Christmas morning in his face. Kayla Huffman's husband Alex posed with the crew and their trophies.

Bridget Johnson was married to Steve for 19 years. Kylie Pitcher's husband, Jesse, owned a plumbing company. Ashley Stovel's husband, Mikey, was a steam fitter. So was Charlie, Heather McDaniel's husband. I met Charlie on the softball field, and he basically from that day always said, you know, I knew I was going to marry that girl. Because you were that good of a softball player? Well, that too, yes.

I gave him a run for his money. When the hunting and fun was over, the men headed to the airport. Sarah Boyd's husband, John, checked in from the plane. John had texted me when he first boarded and said, boarded bourbon in hand. And then right before they landed, he said about to land this bird. Jill Claggett was tucked into bed with her young daughters, waiting for her husband Tommy when the phone rang.

And then I kind of slid out of the bed not to wake. them up, and I turned on the TV, and I remember just seeing the explosion. Fire command. The accident happened in the river. Families raced to the airport as divers searched the icy Potomac. By morning, they were told the rescue mission was over. I literally screamed, what am I going to do? It got to the point where, like, his friends were calling me at, like, five in the morning, and they were like, is he okay? Is he okay?

Is he okay? I said, no, he's dead. He's gone, and it's no longer a rescue. It's a recovery, which means there's no survivors, none. As the wreckage was pulled from the river, federal investigators began a year-long forensic autopsy of the collision. Video shows the American Airlines jet, seen here on the right of your screen, pulled up just before it and the Army helicopter collided. There were obvious cracks in the system. There were obvious holes. Emily Hanoka says she saw those holes. during her time as an air traffic controller

at Ronald Reagan Washington National Airport, commonly known by its airport code, DCA. Her shift in the control tower ended a few hours before the fatal crash. She is speaking for the first time about the stress conditions that she believes set the stage for tragedy. So you had frontline controllers

ringing that bell for years and years saying this is not safe. This cannot continue. Please change this. And that didn't happen. For more than a decade, air traffic controllers warned the Federal Aviation Administration that the tempo of passenger jets and beehive of Army, police, and hospital helicopters near DCA was a recipe for disaster.

The NTSB confirms between 2021 and 2024, 85 near mid-air collisions between helicopters and commercial aircraft at DCA were reported to the FAA. And 60 Minutes has obtained documents that revealed just one day before last year's fatal crash, two separate passenger jets had to take sudden action to avoid colliding with Army helicopters. The warning signs were all there. Controllers forms local safety councils. And every time that a controller made these safety reports, another controller was compiling data to back up the recommendation. And many recommendations were made, and they never. went too far.

DCA is unique. It's owned by the federal government and the number of daily flights is ultimately determined by Congress. Since 2000, lawmakers added at least 50 flights to the already congested airport and approved another 10 in 2024.

Some hours are overloaded to the point where it's over the capacity that the airport can handle. Was there pressure to get more planes in and out? Yeah. there was definitely a pressure. If you do not move planes, you will gridlock the airport. DCA moves 25 million passengers a year,

10 million more than its intended capacity. Its location near the heart of D.C. makes it popular, but also problematic. Restricted airspace near the airport shields the White House, the U.S. Capitol, and other government buildings. For years, funneling planes and helicopters into the same narrow corridor over the Potomac. And Hanoka showed us on her map of the airspace

why the tarmac is just as tricky. There are only three short runways at DCA and none are parallel. And so if a plane's coming in, because these runways intersect, everything is connected. Everything is connected. There is no independent operation, not DCA.

DCA's main runway, runway one, is the busiest in the country, with over 800 flights a day, roughly one every minute. To make it work, Hanoka says air traffic controllers often relied on what they called a squeeze play. A squeeze play is when everything is dependent on an aircraft rolling, an aircraft slowing, and you know it's going to be a very close operation. So they're really just one's going up and one's going in at the same time, and that is a really common operation.

Two airplanes on one runway within seconds of each other. Is that normal at other airports? No. So you'll get new controllers come in, so they've transferred from other facilities, and they'll look at the operation and say, absolutely not. And they'll withdraw from training. And that when I was there, it was about 50%. 50%. About half of the people that walked in the building to train would say absolutely not.

A year after the crash, nearly one-third of the controller positions in the DCA Tower are unfilled. It was surprising walking into that work environment how close aircraft were. It's just kind of accepted there? Yeah. This is what has to happen in order to make this airspace work. And it did work. It worked until it didn't. In January, the NTSB determined the mid-air collision of Flight 5342 and the Black Hawk helicopter was preventable.

In its 388-page report, investigators didn't identify. a single cause of the accident. Rather, they called out systemic failures, including ignored warning signs about risks and a helicopter route that was designed so poorly that in some parts of the sky, it allowed for just 75 feet of vertical separation between helicopters and passenger jets. I flew these routes hundreds of times. During his 20 years in the Army, Tim Lilly flew Blackhawk helicopters often down the Potomac River near DCA. The night of the crash, investigators say, the Black Hawk crew was relying on what's called visual separation, literally just looking out the window to avoid nearby passenger jets.

To apply visual separation, the pilot has to positively identify the other aircraft. And say that's the plane you're talking about. That's the plane. And he has to maintain constant surveillance on that aircraft, which is impossible under these conditions. Impossible, he says, because the crew was likely wearing night vision goggles, which Lily says limit what a pilot can see. I help people out with this at home because I think we've all watched enough movies where you see somebody put on night vision goggles and they can see everything. But that's not the case. Especially under these conditions, that's not the case. So when you have a lot of bright lights like you do in, you know, Washington, D.C. area, everything gets washed out

through the goggles. Care Care 1, Washington, International Automator, 2-Nogne-R-0-0. The NTSB built this simulation to show what those Black Hawk pilots saw, or rather, what they couldn't see. That green circle indicates the pilot's view wearing night vision goggles.

That purple circle is the American Airlines jet they were supposed to be looking out for. You can see how it's hard to distinguish between an airliner and ground lights. Night vision goggles also limit peripheral. So the crew on a training mission didn't see flight 5342 until it was too late. So the proper way to fly that is constantly scanning, always move in your head side to side because your field of view is limited with goggles.

But why is that kind of training happening in this airspace where it's so busy? The military would say, this is where our mission is, this is where we need to train. And to some degree, I agree with that. But those training environments, they should be. nowhere near commercial airliners. Tim Lilly is now advocating for changes to make the sky safer. His son, Sam, shared his love of aviation, and in the cruelest twist of fate, was the first officer on American Airlines Flight 53-42, one of the 67 killed in the crash.

And I never thought to warn him about the helicopters because I just didn't realize how far the safety margins had slipped since I had flown those routes. This was a system that failed the people on the aircraft, on the helicopter, in the air traffic control tower. Jennifer Homondy is the chairwoman of the NTSB. After a year-long investigation, the agency suggested 50 safety recommendations to prevent similar accidents. If everybody knows those close calls are dangerous, then why didn't anybody step in and say,

We have to lighten the load here. The air traffic control tower the entire time was saying, we have a real safety problem here, and nobody was listening. It was like somebody was asleep at the switch or didn't want to act. It is a bureaucratic nightmare. Immediately after the accident, the FAA moved some helicopter routes away from DCA and ended the use of visual separation. Earlier this month, it expanded that,

to busy airports across the country. In a statement to 60 Minutes, Transportation Secretary Sean Duffy said he's helped secure more than $12 billion to, quote, aggressively overhaul our air traffic control system. But the problems at DCA continue. Since the crash, 60 Minutes has learned at least four times aircraft and helicopters have gotten too close, triggering safety reports. It is unconscionable that we are having to be. be here right now. Some of the families of Flight 5342 are now fixtures on Capitol Hill,

advocating for aircraft surveillance technology that might have saved their loved ones. Jennifer Homandy says if the FAA and lawmakers don't move quickly on safety legislation, they are clearing the path for another disaster. I imagine most of them fly in and out of DCA. They do. So what would you say if they were listening? I'd say, why do we always have to wait? until people die to take action. At Desjardin, our business is helping yours. We are here to support your business through every stage of growth, from your first pitch to your first acquisition.

Whether it's improving cash flow or exploring investment banking solutions, with Desjardin business, it's all under one roof. So join the more than 400,000 Canadian entrepreneurs who already count on us, and contact Desjardin today. We'd love to talk. Business. When WestJet first took flight in 1996, the vibes were a bit different. People thought denim on denim was peak fashion, inline skates were everywhere, and two out of three women rocked, the Rachel. While those things stayed in the 90s, one thing that hasn't is that fuzzy feeling you get when WestJet welcomes you on board. Here's to WestJetting since 96.

Travel back in time with us and actually travel with us at westjet.com slash 30 years. Now, Holly Williams on assignment for 60 minutes. When America went to war with Iran last month, the US military faced an enemy using mass-produced drones to deadly effect. The same weapons have been used for years in Ukraine, some of them supplied by Iran to Russia. Unmanned and remotely controlled, drones have transformed the Ukrainian battlefield. They're estimated to inflict around 80% of combat casualties on both sides. The technology is nothing short of revolutionary, and it's evolving rapidly. As we discovered, to adapt to the new era, the US military is learning lessons from Ukraine.

Forget everything you think you know about warfare. The traditional front line in Ukraine has expanded to a roughly 10-mile-wide strip called the Kill Zone. Anyone who sets foot there can be spotted by a drone. operator and hunted down. This was a narrow escape for some Ukrainian soldiers. They call these Frankenstein tanks, retrofitted with cages and mesh to deflect drone strikes. Netting covers roads close to the front, designed to catch them before they hit their target. To evade interference from electronic jammers,

Both militaries launched drones attached to miles-long spools of fibre optic wire, leaving behind a digital spider's web. But the drones are not just in the air. Continuously innovating. Yes. Beside a frozen lake, Ukraine's security service took us to see one of their most treasured weapons. I mean, it looks a bit like a fishing boat scout. That's an outboard motor.

Yeah, yeah. It's a sea drone. developed in Ukraine called Sea Baby. We're protecting this operator's identity because he's a target for Russian assassination. What's the payload on this? It can really take 2,000 kilograms. 2,000 kilos of explosives.

Is that enough to take out a Russian warship? Yes. Produced for around $300,000, Ukrainian sea drones have destroyed warships that cost tens of millions. Ukraine says it's used them to sink or disable 11 Russian vessels. Which one is more useful? A war ship or a sea drone like the sea baby?

Sea drone. I think it's really hard to destroy these drones because they are smaller. That's why to have like 10 ships like this is much better than one big one. Wow. To be clear, you're saying you'd rather have 10 sea drones than a warship. Yeah. Necessities, the mother of... Alexander Commission started out the war as the CEO of Ukraine's railways.

He was so good at his job, helping millions of Ukrainians to evacuate, that President Vladimir Zelensky recruited him to become the architect of Ukraine's drone program. Cheap, fast, efficient. Commission told us he helped boost Ukraine's production from 2,000 drones a year to 4 million. For the outnumbered Ukrainians, the inexpensive new technology has allowed them to level the battlefield. It's a data-driven war. We speak numbers. It's a numbers game. What do you mean by a numbers game? We have to count everything. We have to count number of drones we use, efficiency of each of them.

Cost to kill for every Russian. And what is the cost of killing every Russian? You would be surprised, but the cost of killing every Russian is less than $1,000 now. That's why they send so many people to die on the front line. They don't count them. They don't value them. Would you want to be in Vladimir Putin's shoes right now? No.

Strategically, he lost. He wanted us to become weaker, became much stronger. Ten retired U.S. generals told us they agree that Russia isn't winning the war, despite its territorial gains. Some caution that Ukraine isn't winning either. But with the help of drones, has managed to draw Russia into a stalemate. This is like a kind of obstacle course for drones. Ukraine's military has set up drone training academies to teach the new technology.

Patience and practice. Yes. I mean, practice makes perfect, am I right? and the rapid shifts in tactics that come with it. This ground drone mounted with a 50-caliber machine gun recently held off a Russian attack single-handedly for 45 days straight. In January, three Russian soldiers surrendered to a similar robotic drone. Our main idea, we can send a robot and to not risk with a human life.

So for us, it's a human life, is the most important. says it makes more than 95% of its own military drones, harnessing talent from some unusual places. Roman Tukachenko is a former brewery engineer who founded a company called Tencore and developed these remote-controlled, armored evacuation drones to transport wounded soldiers. They gave us a demonstration at a military training ground and claimed the drones have saved hundreds of lives. How do you figure out what your next design needs to be? We are working with the end users. End users, that means the soldiers who are on the front line.

Yeah. The soldiers said we need a drone to do evacuations and you built it. Yep. That's how it works in Ukraine. We are designing for soldiers. The same drone base can be adapted to mount a 40-millimeter grenade launcher, controlled from a bunker which could be hundreds of miles away. When it comes to drones, how quickly is the technology changing?

Innovation cycle is roughly one week. It means from the point you send a drone to the front line, get the feedback, change something and get the new version. It could be as short as one week. Are the Russians also innovating? Yes, definitely. We have to admit it. Who has the edge? At this point, I would say that's equilibrium. Equilibrium in a drone arms race,

and both sides will take any help they can get. Air Logics makes aerial surveillance drones for the Ukrainian military. Their production spread across more than 20 sites to minimize risk, because they've already been bombed twice by Russia. It's a dangerous business, but the company recently secured over a million dollars from an American investment fund that specializes in Ukrainian drone technology.

It's run by two former US Marines, William McNulty, who has a background in humanitarian work, and Lenore Karaffa, who built a career in finance after leaving the military. They told us their investors are wealthy individuals who support Ukraine. I worked at one or two jobs after the military that were more about the money than anything else.

That is not my main motivation. You didn't join the Marines for the money? What's your main motivation? Service, patriotism, democracy, mission. And Ukraine takes all of those boxes. It takes all of those boxes. I fell in love with the Ukrainians when I arrived. How could you not?

And how can you not just come to help the people that are literally fighting for what? NATO was created for to stop Russian aggression. At a NATO training exercise in Estonia last year, the Alliance tested its vulnerability against drones. Around a thousand NATO personnel were defeated in the drill by a group of drone operators, some of them Ukrainian. Is this a revolution in warfare?

It is. No question in your mind. No question. You know, in every war, like there is innovation, from going from horses to tanks to machine guns, and then tactics evolve in response to that. And that is why it's just incredibly important for the U.S., for our European allies,

to learn these lessons from Ukraine. There's a real risk that the U.S. would lose its military supremacy if it doesn't adapt to modern conditions on the battlefield. We're going to be going up against these same unmanned systems that Russia is using against Ukraine. The US military told us it intends to hang on to its supremacy. Not by buying, stockpiling or replicating Ukraine's drones, but by tapping into the same passion for innovation the Ukrainians have.

At the Weisbaden garrison in Germany. Cable channels you run through, keep everything nice and flush. The forge is one of dozens of drone innovation labs set up by the US military around the world. Props are good. Any service member with an idea or just an interest can request to spend time in one of the labs. The legs slide out and just add a space area.

It's adding a culture of innovation, and that's new. That's not something that we've really seen in the last 20 years. Is it possible that a soldier will walk into one of those innovation labs with an idea that could be a breakthrough in drone technology? It's entirely possible. The thing with drones and innovation is what I would describe as unlimited innovation potential.

If you can think of it, you can make a drone do it. Expedited basic training. Captain Ronan Sefton was first deployed to Germany with the Army's second cavalry regiment. Not long after Russia launched its invasion in 2022, his job was to give basic training to over 8,000 Ukrainian soldiers. But he told him,

almost immediately the Americans began learning from the Ukrainians. The first really poignant lesson for us was there needs to be more drones. They need to be everywhere involved in the training to add to the realism. So the Ukrainian soldiers were giving that to you as feedback? Absolutely. Did you then talk to your commanding officers about it? We went to every senior commander we could. The thing that we wanted to communicate was this is important, it's changing warfare,

and here's how we can actually implement it now. We're already doing it. We should scale this. The message got through, and now SEPTons joined the army's Ukraine Lessons Learned Task Force. It has the job of translating experience from Ukraine's scrappy fighting force to America's sprawling military. He told us the new technology does not make the US military's traditional firepower obsolete. But it needs to adapt urgently.

countering the drones developed by America's adversaries. You still need howitzers, you still need Abrams, but you have to figure out how to get the drones to work with the howitzers and Abrams. Exactly, and that's the challenge, but also the goal to become ready for the next conflict. We see it with the armed forces of Ukraine. They have learned these lessons through blood.

There will, of course, be additional lessons that we will learn, perhaps through blood. But it will only make us better at what we already are. The day after that interview, the United States went to war. And the Iranian drones began flying. The first Americans killed in the conflict were targeted with a drone. The US military is now learning its lessons in blood, just as Ukraine did. The next breakthrough in battlefield drones?

Drones working together like a swarm of bees. Exactly. Pretty scary. It is scary. Absolutely. At 60 Minutes Overtime.com. Where are my gloves? Come on, heat.

Winter is hard, but your groceries don't have to be. This winter, stay warm. Tap the banner to order your groceries online at voila.ca. Enjoy in-store prices without leaving your home. You'll find the same regular prices online as in-store. Many promotions are available both in-store and online, though some may vary. Imagine in the 21st century discovering a marvel on par with Mount Everest or the Grand Canyon. It happened in 2009 with the revelation of the largest cave passage in the world.

It's in Vietnam, and they call it Hang Song Dong, Mountain River Cave. An intrepid British explorer, Peter McNabb, led the first team through this epic, underworld of caverns, the height of skyscrapers. McNab is to caving what Armstrong is to the moon, the first explorer. Recently, we asked McNabb to show us this wonder of the world. But before we begin our trek, we really have to show you a preview of where we're going. Simply glorious. This was the moment Sondong caught us in its growth. grass, sunbeams cascading 120 stories from a break in the ceiling, groundwater above us slipping through the light like rain, and rock reflecting what seemed like the only sound in the

world. Not many have stood in this space that transcends time. It was a reward for our journey that began days before. The only way to Sondong is on foot, a trek of a day and a half. We had a party of 53 moving in groups, mostly porters, heaving, camping, and TV gear, plus experts in safety and climbing. There were 20 river crossings,

water flowing through limestone. Two of the essentials for building caves. This is the slender center of Vietnam, the Chusun Range between Laos and the South China Sea. We were following the Vietnam War's Ho Chi Minh Trail, through a jungle where tigers are not unknown, and leeches are plentiful. Leading us were explorers' explorers'

Howard Limbert, whose work in Vietnam over 30 years, discovered 500 caves, and Peter McNabb, whom Lembert sent to be the first in Sondon. I find it an adventure going, exploring, and not quite knowing what's around the corner and just sort of finding your way through, and things reveal themselves, like big chambers, big passages, or tight, narrow bits, beautiful formations. And there aren't a lot of places on Earth. that you can discover for the very first time. No, you have to look pretty hard for them.

You have to look pretty hard for the entrance to Sondong. You'd hardly notice but for the writing on the wall proclaiming the miracle of Ho Khan. In 1990, Ho Khan, a villager, discovered this entrance after he sheltered here from a storm. He told us, I was collecting wood.

I saw a sinkhole and I felt something strange. The strange feeling was wind blowing out of the ground. Cavers know that's the breath of a tremendous cavern. In 2000, the British cabers asked young Hokan to show them, but it took eight years he'd lost it in the trackless jungle. In 2008, I finally found it, he told us. In 2009, they started exploring. That exploration began here.

We're just inside, looking back toward the entrance above. The first obstacle is a spectacular 30-story wall that our climbing team showed us how to descend. Can you step to the left side? Darkness would be nearly total, but we lit it so you can see. Peter McNabb was the first to do this. In 2009, he and four others on his team were dropping into darkness. There's an obvious big black hole where you're heading towards,

and you just sort of skirt around and look around and find, this way is pretty good, this way it works. Quite often you get stopped, can't get down here. You just basically feel your way through the cave by trial and error. You had no idea what was beyond the light on your helmet. Yeah, no, we didn't at all. Every corner you went around was completely new, completely exciting, and it just kept getting better and better as you went into the cave.

It was absolutely spectacular. Spectacular like the entrance we just repelled down. Look at the two men, halfway down holding lights. At the very top is the entrance, and the last daylight we would see for a while. At the bottom of the climb, we met the architect of Sondong. The Rau-Tung River. Its waters are acidic, so it's really good at dissolving limestone. Well, this is a pretty good setting for an interview.

Yeah. In camp, we spoke to Purdue University geologist Darrell Granger, who came here in 2010 to figure out when the river started its project. We found a nice package of sediment further in the cave, and that dated to about two and a half million years ago. That's when the river first found a tiny crack in the limestone ridge. The width of a hair, maybe, right? That's all it takes to make a cave. The water started flowing through it and dissolving it bigger and bigger and bigger. We still have water going through it today, so it's continuing to get bigger as we speak. Our exploration of the cave took three days and two nights.

The length is 5.6 miles. It's 65 stories tall and the width of one and a half football fields. The great pyramid of Giza would fit easily. A 747 could fly through the biggest passage and not scrape a wing. Sometimes the only way forward was the width of our shoulders. But we noticed in the broadest caverns you often lose the sense of even being underground. What reminds you is the isolation. No cell phone, no satellite, we were cut off from the world.

Roughly halfway, there was a light ahead. There are two skylights where the roof collapsed. For us, a break from total darkness, and a chance to show you the scale. Geologists call these holes, Do lines. The word has European roots. It means sinkhole or depression. And this dolein formed because the roof over our heads, the limestone, is a little bit thinner

here than it is in the rest of the cave. Then as the cave grew wider and wider and wider over millions of years, it was unable to support the roof above. It all caved in right here. What's remarkable about it is that it allows light into this cave that would otherwise be utterly dark and it allowed the jungle to come inside the cave. Like everything else about the cave, this dough line is enormous. It's 450 feet above my head.

In other words, about the height of a 45-story building. We stopped here with Howard Limbert, who's a explored Vietnam since the 90s. When my producer Nicole Young suggested the story, I turned her down. I said, Nick, it's a hole in the ground. Yeah. What was I missing?

You're missing best adventure that happens in the world. Something no one's seen before. That's the beauty of caves. If you're climbing the mountain, you can see where you're going. But in a cave, when you go in, you don't know what he's going to do. Your father was a caver. He was, yep. So he was a caver in Scotland.

Peter McNabb, the first in Sondong, has been caving since he was a boy. You grew up in a cave. Not quite, but within a mile of it. McNabb is a construction manager in New Zealand, big projects like hospitals. But you get the sense he does that to pay for this. In all the caving that you've done, what is the closest call you've ever had? I've been stuck. I've had rocks collapsed and I've been flooded in. He was stuck a few years ago when he went headfirst into a crevice that Kavers call a squeeze.

McNabb couldn't back out. A partner found him and used a knife to rip away his coat to give him the spare half inch he needed. Did he pull you out by your feet? Pretty much. Yeah. You are still exploring this region? Yes, yes. We come back every two years.

and we've barely scratched the surface of the caves in this area. There may be another biggest cave in the world. They could well be. Truth is, McNabb's first expedition in 2009 never reached the end of Sondon. Beyond this underground lake, he discovered a 30-story wall and ran out of time before he could scale it.

Take in, take in, take in, take in. We climbed it on our trek and understood immediately why they call it, the Great Wall of Vietnam. Keep the line tight. Take in. Excellent. Take in on the lifeline. It's a 300-foot climb on slick rock with no foothold anywhere. Take in. Excellent. Scott, that's really good. Come right up to the corner. It's challenging enough until you realize, of course, you're doing it in the dark,

and it's essentially raining. The groundwater is coming from the roof. So with everything wet, you find yourself slipping back while climbing up. But our team got us up and over, drenched and a little exhausted. Well, we saved the best for last. We've made it all the way through nearly, all the miles of the cave over three days, and now we just have a little bit further to go. In fact, I can see the exit from here.

We could see it, that light up there, but we still had quite a climb to make. We learned by the end of our trek that Sondong may be even larger than we know. Hundreds of feet below that lake behind us, the water is draining somewhere. There could be more caverns beyond. It's the work of millions of years, likely to continue for millions more. Unimaginable time. Measured by a pendulum of light, illuminating the splendor of one of the greatest marvels on or

under the earth. The last minute of 60 minutes. As America celebrates the 250th anniversary of independence, we wondered about a game plan for the country's future. So, Hall of Fame basketball coach Mike Cheshowski drew one up for us. To build a championship culture, you need talent and character. You then develop the values of that culture. The best teams have the best values.

We had seven. Integrity. Do the right thing. Respect. Everyone is important. Courage. The courage to say or do what needs to be said or done in that moment. Selfless service.

Loyalty. Duty. The dignity of work and trust. Values-based organizations stand the test of time. Our country has great talent. And for 250 years, we have proven that we stand unshaken by the tests of history. Moving into the future, we must continue to teach, celebrate, and most importantly, live the values that have made America the best country in the world. I'm Scott Pelly. We'll be back next week with another edition of 60 Minutes.

There's a lot going on right now. Mounting economic inequality, threats to democracy, environmental disaster, the sour stench of chaos in the air. I'm Brooke Gladstone, host of WNYCs on the media. Want to understand the reasons and the meanings of the narratives that led us here and maybe how to head them off at the past? That's on the media's specialty. Take a listen wherever you get your podcasts.