Transcript for Matt Gutman Reporter's Notebook: 'The Boys in the Cave'

Welcome to the reporter's notebook it was one of those stories that captured the world a boy's Thai soccer team trapped in a flooded cave. As we all watched on pins and heels waiting to see if rescuers would be able to get them out and we now know of course. That ended with one of the most amazing rescues in history. Luckily Matt Gutman was there on the ground as it happened and he's here with us today to take us behind the scenes with his new book. The boys in the cave Matt can cracks on the book coming out first of all thank you Diane and thanks for Kona hi Alice always great to talk to you. Love getting the behind the scenes on stories like this and Anderson you brought some photos if you want to. I did so I just got these photos so basically and Kate was flooded. The very last moments of the rescue. But all the boys got out but there for Thai Navy SEALs who were bring up the rear they'd spent a few days at the boys just to assure them. It's gonna be okay and they will be there for the duration but after the last two Thai navy seal divers came out the cape flooded. And everybody started bailing. It was indicate basically filled up with water and it stayed that way. Until these folks came in to start cleaning it up my accidents like this time capsule of those last moments just as those people. The Thai Navy SEALs were rescued and EC. Bottles strewn everywhere have there are plastic chairs. And hundreds and hundreds of air tanks just left to right there on the ground where they wore as people fled the cave helter skelter. When that water came up I think it had a chance to go back and get any that's after the time is literally not nobody's been in their sits flat it's incredible and and Thai government has. Cordoned off the KV used to be open to the public and nobody was dumb enough to go in there during the monsoon season not that the boys did. But typically they didn't need to have to send Saddam but now it's become this. Next up for visitors they've. Light incense and offer the spirits of the cave. Papaya juice and all these different offerings on it's become this this. Fantastic tour tourist attraction in Thailand it's it's just the interesting thing that nobody's been there are now. The whole place is cut off by these giant chain link fence. He can't get into Bradley used to be it is really remote deserted little Caylee nobody know visited massive write action but. I mean to many people a miracle happened there. I just want to say one more thing about the cave itself so I got the Thai Rangers to you let me end because I was doing a book and I just basically convince them. It's pretty incredible so parts of the cave are. You know its highs as chair right. It's chill feed and uses tiny hole but that main entrance which these guys took mean to see this is one of those tight tunnels. That you're seeing. Basically about six feet high that's the cave itself that chamber nine were the boys were hunker down you can see how me seated they were. After twelve days of not eating but. Parts of it. Were easily big enough to fit a 747. And how us you know having reported on it for months and then finally seeing it. It was seventy yards high almost time enough to fit a hockey arena and bumped 200 yards long that first entrance that first chamber. It was so amazing game to see it in person I can see why. So many people been enamored with an eye can see way. The coach took the boys in as this in a fantastic team building exercise. An excursion for those boys. Obviously he didn't think it would end up the way it ended. Cores in I have been an and it's similar cave. It was not in Thailand it was in Belize but even be. Did that in these expenses you go in says parts of the kids like you're mentioning and there are huge I mean it's like you're in a dining hall or something even lighter and then you crawl there was space in your in this tiny little section and so to think in my mind about what it would have been like to go through that cave in the dark. Under water I can imagine how these rescuers were able to get these plays out and I think that's what. Made this story so compelling to so many people they're trying to put themselves in their place they almost can't even imagine what it's like. And you're on pins and needles thinking how on earth are they gonna do this I'm wondering what it was like for you to actually be there. As all this was happening is just watching on TV we we were on the edge of our seats as one by one we start hearing these boys are making it out what was it like they're on the ground. We didn't know how much we didn't know. Right. We figured okay somehow they figured out a mechanism to get an out but what the Thai government told us at the time was actually wrong. They didn't even know. How the boys were being extracted they said two divers to a boy they did not tell us that the boys were completely sit dated this is you crawl in Connecticut that's me. Until we did we simulated that would instantly we went through a nearby cave. And you know this is one of the baker chambers but. I think you'd probably in his spare you seeing my butt. Because I had to slip there through what of these tight spaces and all you see is might mice might dirty trousers. So I think we're gonna spare viewers from that but. That's where the incredible things that the divers go through is. They have their air tanks. And they have these boys and it's one diver to one point and the boys this is a secret that your only know learn in the book nobody else's have reported this. They were bound hands and feet. With zip ties the receipt dated so heavily with -- mean the could have knocked them out the could have amputated and arm don't open heart surgery that would have felt a thing. And they were hauled out of the cave and they kept having to be recent dated all along. Because. The divers were concerned that if they came to they would panic and start ripping off their own mask or the divers mask and that bill could die. And so they were taking the methodically through. These spaces with C dated boys bound hand and feet through areas as you know far off the ground as its chair. Putting the boys through one of the divers got lost and his boy almost had he was hypothermia can almost died another boy eight. Stopped breathing after the second dose of sedation. And they didn't know if he would survive. It was touching some advocates are hyperventilating when there's a dated and these divers are in the cave. In the dark. And underwater at times it couldn't even tell if the boys were briefed this is so much pressure sometimes the only way they could tell. Gays they kept the boys really close to their face because they're diving they're holding on to straps. And they could feel the bubbles coming up the side of their mouth that's the only way they could tell that the boys were still alive. And so when they finally got them to chamber three which is about two thirds of the way out of the cave and that's where the US. Air force special tactics team was waiting with. A real medical. Crew and they shove them out in two. That chamber out of the water and Mitzi is your life because they had no idea and then especially for for the first four boys. Everybody in that chamber sort of waited as the medic who listened in he put his ear on. The boys neoprene suit and they were so skinny guitar to actually hear heartbeats that put their urine. Finally seconds would go pies take. He's a lot. And everybody in that. A young people said the Chinese these are taking video. Are already exist today. It was just this incredible moment my all these from all over the world they were Chinese and Thai and brits and French and gains. And probably others as well Finns who weren't Carlos came together to help save this boy it was incredible. And I you know you mention this a lot of people didn't know this until the book that two of these boys did come very close to losing their lives here. Very close and going in the divers estimated that 75 to 80% of the boys would die. They really thought that between eight and ten of the boys would die during the extraction. The boys had been in a cave in the dark for. Nearly three weeks at this point. They add up only had a few meals under their belt when they were found. They'd been deprived of light of air they were breeding 15% oxygen. And some of the net had had the early stages of pneumonia. And. They didn't know if they could make it out that enough they're physically capable. But the fact that they survived is remarkable. And they really didn't see it and you know. I don't know if you can see these videos this is then just trying to still look for them in the beginning. And that's when the boys were found to have the space blankets they were freezing and there. The it was 73 degrees in chamber nine but the boys were already freezing all the time because the bodies had eaten away. Most of their muscle and their fat right and so they were called cold all the time. Just trying to survive and winds keep blankets were actually essential if you think the deck and not have. In more stacked against them which is what makes the whole conclusion of all this so amazing the fact they all got out the coach got out. I mean these divers are true heroes. And that this is a rescue that also almost didn't happen that's racking that the government not necessarily knowing what the plan was. Even as it was going down but they almost put the kibosh on the cell together. They had promised the public a zero risk option they said we're gonna get all the boys out brawl and a walk out of the cave they hope that they would walk out of a cave. After the monsoon season when all that water you see. Just clears out clears out or drain. But this American special tactics team and the British divers who were really that the people were able to go deepest earliest said hey listen. If you wait until the end of the monsoon season. They were either drowned to death by these rising waters we have another months and coming in a couple of days it will start to death because we can't get food out there. Fuel is 68 because if they don't drown the oxygen level that team is 15% if it gets any lower. They will die rain carbon monoxide was rising because they it was a trapped chambers so. We are you read out their breathing out carbon monoxide carbon dioxide and they were this. So is there were losing an oxygen gaining carbon dioxide in the cave. And their chances of survival are increasingly. Decreasing. And they said if you don't pull them out they're all gonna die if you do try to go for this. Rescue dive maybe we can save some of them now. And the leader that incident the incident command leader whose name is governor in Iran sacked symbol what do you consider a successful mission. And the American major was in charge of it Charlie Hodges. Said honestly if we bring one boy out to his parents. I would consider that a successful mission. You know so the Thai government is going from. We're gonna save everybody. Q being presented with the option of well made one that made Canadian success. Obviously that was a tough pill to swallow but anti government did. The courageous staying. By biting the bullet in deciding hey we're gonna try to save some of them on even if we can't save all of them. And at least provide one family or a couple of families with their son and you know and we still have the bodies of their kids and that's what the divers thought they're like well. If we can't rescue them alive at least we can bring out their bodies. And I know you have now spent a lot of time with those divers to. It must've been indescribable for them to be able to walk way from this and say. Holy Kelly save them all especially given the expectations that they went into this with how to they look back on that Dana. They can't believe it either and it's in three days that they honestly didn't think that they'd pull it off and by the second day they start to think well will made that we can do this and that's when the pressure started rising. And after that second David Thai prime minister. Came by and he was cheering and then. You know Elon Musk showed up and it started to become a real circus and that's when the pressure had of that third day was really rising these guys starting getting nervous and everybody now expects us to save all of these break but we still don't know we can pull this off. Because the last four boys were the weakest two of those boys had pneumonia. And they had thought that big and try to bring the strongest out first. And they didn't know if the last four boys which included the two smallest weakest voice would make it said the pressure was on until the very. And now how did they pick an Arab he knows that had they pick the order so there's a bit of controversy that controversy but little mystery here so the police told me. That they decided to do it based on an order of who lives farthest away it's actually quite quick. They said well we have our bikes still out parked outside the case we have to ride home up so we want to give the boys who live farthest away a headstart that. And the ones who live close is wolf you know. Elliott he had no idea with waiting for you got that they had no idea eight you know there are thousands of literally thousands of people waiting outside and other parents were there they had sent. Once they were discovered they sent letters to their family Tseng. You know I'll help you back at the store you know as soon as we get out please tell my teacher that I hear all of you know complete a coworker I doubt literally intersected kids. Ensco in the had no idea the that the media circus that awaited and the amount of attention that they would get when this was all over. They had been shielded from it by the coach and the divers say they just didn't want them to focus on that they wanted him to just think about getting out making sure they can survive. And what are the divers is the last ever going into the last boy thinking thanks a lot. No pressure is so the last diver. Actually had a successful dive he was okay it was the second to last diver who got lost. And really had some trouble. So it's there's sort of a jug handle in one of the chambers and he basically went around in the circle he it was so dark he lost the guideline and you swimming with his boy. And he's it was Hong. And he lost the guideline and he couldn't find the way out of the cave and he basically had to double back when and his voice started freezing to death. And he was unconscious he recent dated him but he didn't know what to do was only because the very last divers came out with. There boys. That was last diver and then the anesthesiologist. Came out that day he realized oh that's the direction of the exit. And the anesthesiologist. Had to take that last boy because. Bomb the diver who got lost with so rattled. He'd almost died. He'd almost caused this boy may be to lose his life so it was really really touch and go until the very end. And the fact that became flooded right after they've got allies and I don't eat. It's its main for a movie ON and yet happened in real life. It's a they didn't know Susie US special forces team who organizes it organized and they had the medics in that area who made the initial assessment of the boys. And they were given the code word landslide. In case anything went cataclysmic re wrong. Rock slide somebody got hurt or any anything that forced an evacuation in so. When McCain started flooding at the very end because the pumps broke and the water started rising they yelled out landslide labs like landslide. And everybody started bailing. And they had to wait for the last four Thai Navy SEALs and as their exit there is one exit it was at a tunnel that was basically had high. It was silly to the very rich top and made and have scuba equipment scenario makes me nervous is tell me now are in right now ring joke like this as the the last that they waited for the last night divers. And they all got out with seconds to spare and they. Sort of sift the air puckered their lips and sit the air at the top of the tunnel basically bouncing up and down. And that's how they made it out alive without drowning and then no one has been the case since then and then you see those pictures so it's just an incredible story. Freely and him and what's great about the book is that there's so much in there that keep people think they know so much about the story but there are so many little bits and pieces that we don't including some of the ones you just shared. But there was also a rescue before the rescue. You know the story so well Diane otherwise tension. That hit the of those British divers and I mentioned went on a reconnaissance mission the first day that they got there which is a week into the rescue pretty much. And they had no idea what they'll find who they would find and though that the water had really flooded to a high level. And a day earlier. The Thai government had ordered a complete evacuation of the K now what these two divers didn't know. Is that there were four tie pump war person who got marooned about a thousand yards in. It's that they're doing a recon mission trying to figure out what gave his like with the waters like Italy that pop up. And they see these four guys like. Don't let who are you know what do you care. Many outside of boys suckered right. And they had to rescue them one by one they were prepared for rescue and that's when they knew that they needed to sedate the boys. Because as they started coming up with. These guys that they had to rescue they were sharing their respirator when and regulator. That the the guys were rescued started swimming away inclined to the exit. And they realize that they panicked each of them had panicked in the water so hard not tonight. And you're talking that was look up 5060 foot dive and they would have had to have done a mile underwater with those boys. If they had been awake they just would have lost it ran would have panicked and that's when the tide did the British divers in new. That they had to completely sedate the boys in order to have any chance of affecting a successful rescue. On thank god they did and nomad this I mean for me this story is just it's incredible that I know you have traveled the world you've covered countless stories. What was it about this on that made you decide I have to read a book about this. There were so much we didn't know and the chances. What I just didn't know how much it didn't know. And then once they started reporting more about it. I a entered this world at a hadn't even expected. You know the world of of Thailand and buddhism. And diving. And caves and these rescuers in this very knee should thing of cave rescues it was just an incredible thing and I guess you're seeing here not see the helicopter the rescue helicopter there it is that they used to fly the boys to safety. There's just so much we didn't know. And just every little tidbit I got was fascinating. What's this 10 this is the entrance to the cave and you can see and that's when the pump trucks by the way. And obviously that's one of the tunnels luckily again you're not seeing the but picture here your very. I we're waiting for that I thought I was good TV when I'm I don't then and I'll I see is like my my my experiment I spent there. And it was not a great thing. They I was just so much fun team. Learned so much about something that I thought I knew something about him well now you're bringing us into that you have your teasing us so much about a story we tell you everything about. The book is called the boys in the came it comes out today yes I am so so Palm Treo and doesn't pump for all of you check out the book. That's an incredible story Matt thanks so much for hanging out with us that does it for this reporter's notebook thanks for hanging out with us everybody. Have a great day again the book is call the boys McCain comes out today.

This transcript has been automatically generated and may not be 100% accurate.