and twitter. i'm john quinones. "20/20" starts right now. "20/20" starts right now. was there a moment you thought, we can't do this? >> tonight on an all new "20/20." >> it wasn't whether we could get them out. it was whether we could get them out alive or not. >> the rescue in thailand, now from the divers. >> it could be catastrophic. >> tonight, you will hear from them about that moment of oive or not to dive. >> we have to do everything. >> the green light to go, it was now or never. >> the whole world is watching, and you're telling them that you might lose a couple of the kids. >> i expect anywhere from three to five to die in this operation. >> right here tonight, all new video and details. the practice sessions. >> we did what we call a rock

drill, to make sure that what we planned on paper would actually work. if it's going to be successful, the kids need to be sedated. >> unconscious. they were completely out. >> time was running out. >> this is not a question if the cave was ultimately going to flood. it was a matter of when it was going to flood. >> anything could go wrong, and sometimes it did. >> it came out of my hand, and i didn't know where i was. >> you got lost in there, ran out of air, you die. >> 17 bodies out of that cave, every single one of them alive. >> this is the stuff of movies. >> tonight, "20/20," one way out. good evening. i'm david muir, and this is "20/20." we told you we would stay on this story, and we have. tonight right here, you will hear for the first time, the heart-raciing details from behid scen from the divers themselves now talking to our matt gutman.

>> reporter: under a monsoon-soaked mountain in northern thailand, in the deep-down-dark, a majestic death trap. after nine days of desperate searching, the missing members of this boys' soccer team and their coach are found, miraculously alive. from the shadows of the cave, this indelible image, a ray of hope beamed around the globe. >> raise your hands. >> thank you. thank you. >> how many of you? >> 13. >> 13? >> yeah, yeah. >> brilliant. >> many people are coming. >> many, many people. we are the first. >> absolute elation -- followed very quickly with, "oh, wait a second. now we gotta get these kids out." >> yeah, yeah. i am very happy. >> we are happy too. >> yes, thank you so much. thank u. >> onduk >> reporter: the divers who find the boys, john volanthen and rick stanton, and fellow divers jason mallinson and

chris jewell, belong to an elite british cave diving team with unique rescue skills. in thailand, these volunteers, working without pay, come to be known as "the awesome foursome." >> i never had to think for a second about whether i would go. i think it's human nature to know if you've got an ability, then, of course, you will. >> reporter: the boys get food, mres and company. the military doctor join them in the cave for their duration. >> when they got their energy back, the kids cheerfully talked a lot about where they would go, what they would eat, their plans after they get out of the cave. >> reporter: a u.s. air force search and rescue team headed up by major charles hodges and master sergeant derek anderson, joins the effort. >> we came in bringing our military expertise when it comes to operational command and control. when it comes to, kind of, really looking at a problem set

and finding what is the risk? what risk are we willing to accept? >> reporter: every trip into the cave is filled with peril. a fact highlighted by the death of one of the volunteers. >> a rescue diver has died. >> the man who died was young. he was fit. he was a former navy s.e.a.l. >> reporter: former thai navy s.e.a.l., 38-year-old saman kunan posts on social media about coming out of retirement to help. on one of his dives, something went terribly wrong. he is found unconscious and later dies. it's sergeant sam's mouthpiece fell off. he was trying to grab it, but he couldn't find it. he was trying to take out the spare one, but due to the complexity of the cave, there was no air to breathe. >> we were very sad. the whole world collapsed. >> felt like the whole world was collapsing? >> yes. >> how did that affect morale at the camp? >> obviously, it made it a little more somber.

made it a little more serious. for the s.e.a.l.s, it caused them to re-double their efforts. everybody really got down to business after that. >> reporter: what stands between the boys and the daylight they haven't seen in two weeks, is about a mile and a half underground obstacle course of rocky chambers, half flooded canals and fully submerged sections. the longest of those is 350 meters, the length of seven olympic swimming pools. and it's filled with water so muddy, it's like swimming in coffee. >> you physically could not see your hand in front of your face no matter how close you put it to your face. >> reporter: the american advisors say the divers tell them, bringing all the kids out of the flooded cave alive will be an impossible mission. >> they're tellin' us this is the absolute worst conditions that you can have for a rescue. and it was pushing the envelope for what they were comfortable with.

>> they said, "this is incredibly difficult for us to do, you know, m -- much less a child that's -- that's never dove." >> we always knew we could get them out, it was whether we could get them out alive or not. >> reporter: the thais search for alternatives -- drilling down through the limestone mountain, or draining the cave, or simply waiting for the end of the monsoon season. but that is three or four months away. the thais are calling the shots. but the americans warn them, time is not on their side. >> we knew, at that point, that rains were coming. the plan that we have in place is gonna become unfeasible once these certain chambers and areas of the cave get re-flooded. >> reporter: as if the threat of more rain isn't enough, monitors in the cave detect an alarming drop in air quality. >> translator: the other factor that helped us decide whether to proceed with the rescue or not

was the decreasing amount of oxygen in the cave where the boys and the assistant coach were located. >> we knew that there wasn't a zero risk option. but we knew that the option of leaving the kids there for four to five months was a bad option. >> reporter: they begin preparations for mission impossible, beginning with a key piece of equipment, which the americans supply. >> it was a positive-pressure full facemask that is a piece of equipment designed to go over your entire face. >> to ensure that the boys would be able to breathe, and the full face mask would also ensure that water couldn't get into the mask, an air force officer shoots this cell phone video of the divers testing the plan in a local pool. >> put them in the full equipment that we were going to use. dragged them around with the full first mask in for sort of 10, 20 minutes underwater, so everybody could see what we were going to do. >> it wasn't a very accurate depiction of what the rescue divers would actually be doing. but as a proof of concept, it worked.

>> reporter: the strategic placement of air tanks throughout the cave is so critical. they run a drill, using water bottles as props for scuba tanks. >> laid everything out in a big field. and we had staging points set up in the field. and we had them walk through to make sure that what we had planned on paper would actually work in real life. >> reporter: a single tank out of place, could mean the difference between life and death. >> because the last thing that we wanted was for one of the divers to show up at a staging point and think that there would be a replacement tank there, and there was nothing. or even worse, there's a tank there that was empty. >> reporter: now, all that remains is to deliver the simple chilling message to the thai government that diving out is the only option. >> "we either have a shot, where we could get some of them out, or we leave 'em in there. and there's a very, very high chance that none of 'em survive."

i said, "man, this is our best shot." >> we said we've got a plan. it's a good plan. we think it might work. there's a chance some of the kids might die. >> so, numbers wise, what was the probability of success? >> so, when i was asked that question by the governor, what i told him is, "i think we can probably realistically save 60% to 70% of the kids. i expect anywhere from three to five to die in this operation." >> reporter: that is the heart-wrenching decision confronting thai officials -- to save any of the boys, they'll have to risk losing some of them. >> he said, "okay, that's the best plan that we've heard so far. go ahead and start planning as if you're going to effect this rescue." >> reporter: still ahead, before authorities can even give the green light, there's a catch -- how to deal with the one danger that must be addressed before the divers are even willing to

attempt "mission impossible." >> our fear of the children's fear was -- very much a factor that we took into consideration. we were concerned that they were gonna panic. >> there's potential for them to kill themselves. there was potential for them to kill us. >> reporter: stay with us. your mornings were made for better things than psoriatic arthritis. as you and your rheumatologist consider treatments, ask if xeljanz xr is right for you. xeljanz xr is a once-daily pill for psoriatic arthritis. taken with methotrexate or similar medicines, it can reduce joint pain, swelling, and significantly improve physical function. xeljanz xr can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections, lymphoma, and other cancers have happened. don't start xeljanz xr if you have an infection. tears in the stomach or intestines, low blood cell counts, and higher liver tests and cholesterol levels have happened. your doctor should perform blood tests before you start

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for great taste plus intense craving relief. every great why needs a great how. >> reporter: as storm clouds gather at doi nang non mountain, the rescue team anxiously awaits approval for its daring plan to get that trapped soccer team out of those nearly impenetrable tunnels.

had you waited one more day, what do you think would have happened? >> if i wait one more day, i think that it would have been really difficult for us because the rain is coming. >> reporter: agonizing hours pass. then finally, the word comes down from the thai prime minister himself, the rescue mission is a "go." >> it's about 6:00 p.m. at night. which, thankfully, that was when we finished up with all of our phase one operations. we were ready to go at that point. >> what was your reaction when you finally understood that this is happening? >> relief that we could get on with it but also the nervousness that we would actually have to do it. >> translator: today is d-day. we are 100% ready. >> these are the first boys to be rescued from that cave. >> we see more and more arriving. >> reporter: now, the waiting gives way to sudden, furious action. the media is moved away and a

green curtain is put up to block the cave's entrance, as a parade of divers is seen going in. an enormous cache of extra air canisters is already in place and support divers are deployed in the chambers throughout the cave. but the tip of the spear is that elite foursome of british divers, each of them tasked with bringing out one boy at a time -- >> it was one diver one boy. >> that's correct. >> that's a tremendous amount of responsibility. >> yeah, very much so. >> reporter: but when the brits reach that faraway cavern where the team is trapped, they find the boys themselves are shockingly calm considering the terrifying ordeal they're facing. >> there was no sign of distress and no hint of a problem. extremely confident brave, brave young men. >> reporter: in fact, the thai doctor inside the cave with the wild boars says they decide on their own what order they're going to go out in.

>> translator: it was a decision made by all the boys because their physical and mental condition was about the same. the boys who lived farthest from the cave went first because they thought they had to bicycle home to tell their parents the news. >> reporter: of course, those parents had never left the cave since the ordeal began. but choosing who is first in line is actually no small decision. that boy will be a sort of human guinea pig in a first of its kind rescue. and it falls to mallinson to shepherd the boy out safely. >> how do you pull the short straw of taking the first kid out? >> i volunteered. >> you volunteered to take the first out. >> i'm not one to hang around in the back. i'm usually at the front so i just volunteered. >> reporter: already wearing a wetsuit, the child walks down a steep slope into the water. now it's time for an absolutely critical step, agreed to in advance by the thai government. the boy is injected with a commonly-used sedative called ketamine by australian diver dr. richard harris an

anesthesiologist. and mallinson reveals that the shot is not just to relax the boy, it's to knock him out cold. >> i can't have him twitching around and you know when they start moving their arms moving around. there's potential for them to kill themselves. there was potential for them to kill us. it was much better for me to sedate him and keep him under. >> so it was basically an ultimatum from the british divers that they're not gonna do this operation, unless those kids are sedated. >> they absolutely made that a red line. like, "yeah, if we're gonna try this, and -- if it's gonna be successful, the kids need to be sedated." >> reporter: after receiving that injection, the first boy is out cold and ready for the next step of the rescue. just like in those training sessions, that full face mask is strapped tightly on. a single leak could be potentially fatal. the child is now fully prepped and ready to go, yet the veteran rescue diver is still assailed with doubt. >> i was confident of being able

to take one of those kids and dive them out. i was not fully confident of getting them out alive. >> and why was that? >> because we didn't know at first, how they were going to react to the water, whether the drug that we'd given them would be sufficient to keep them under for the flooded sections. >> reporter: but mallinson is not one for turning back. he enters the cold, murky water with the boy for that daunting first dive stage. remember, it's 350 meters long, . 3 1/2 football fields. what follows next is a sort of choreographed underwater ballet. with one hand, mallinson has to hold onto the guideline that stretches to the cave entrance, while the other hand is holding tight to a strap on the boy's vest as he floats face down. all the while maneuvering around any obstacles in the way. >> i sort of liken it to an underwater obstacle course that you do completely. >> in which you are blind. >> yeah, in which you're blind

and you don't remember all the obstacles on the way in. >> reporter: mallinson says his biggest concern, making sure that face mask doesn't come loose. >> was there a second option if their face mask or their air tank malfunctioned? >> there was no other option. we would just have to swim fast to get through the flooded section to the next air chamber. >> and hope that they don't die along the way? >> i mean that's when we were using almost pure oxygen, 80% oxygen because we had been told that, you know, they could survive for several minutes not breathing. >> reporter: after about 20 painstaking, agonizing minutes, mallinson successfully completes the first dive stage. waiting for him are two support divers who help him get the unconscious boy out of the water. they give him a medical check, but with five more dive stages to go. they are far from out of the woods. >> reporter: coming up, a moment of crisis, mallinson is in complete darkness, up to his neck in water, when the unthinkable happens, his young charge starts waking up.

>> you realize you've got to re-administer the sedation you've got to put them out. >> reporter: what would it take for the veteran diver to get himself out of this desperate situation? >> had you ever felt that isolated and responsible in your life before? >> never. the responsibility was huge. >> reporter: when "20/20" continues. my gums are irritated. i don't have to worry about that, do i? actually, you do. harmful bacteria lurk just below the gum line. crest gum detoxify works below the gum line to neutralize harmful plaque bacteria and help reverse early gum damage. and, now there's new crest gum & enamel repair. it gives you clinically proven healthier gums and helps repair and strengthen weakened enamel. gum detoxify and gum & enamel repair, from crest. gums are good, so is my check-up! crest. healthy, beautiful smiles for life. itshop early to save big!y! and take an extra 20% off! boy's tops and bottoms - just $6.40 women's tops - $23.99

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>> reporter: it's 10:00 a.m. sunday. and the rescue mission is underway. outside the cave families wait with bated breath. inside, british diver jason mallinson is taking a moment to catch his -- with that first sedated boy in tow, he has just surfaced, completing a major hurdle, the first dive of the rescue operation. >> we realized that yeah the mask worked. the drug worked. after that, i knew there's a good chance we can get them all out this way. >> reporter: but mallinson quickly realizes there is a flaw in the plan. he and two support divers have to physically carry the child to the next dive point through a muddy, boulder spiked chamber,

about 1 1/2 football fields long. are you thinking to yourself, "what did i get myself into when you're physically carrying this boy through this cave?" >> this is too much. we shouldn't have to be doing this. you know and diving him out. >> reporter: mallison is now physically exhausted when he dives back into the abyss. along the way he faces a mix of diving through completely flooded chambers and swimming across deep canals with rushing water. >> it was actually harder in the canal sections. because once we were underwater and he was neutral and i was neutral, it's quite hard to swim in a canal and then push a child along with you. >> reporter: mallinson is halfway home and struggling to negotiate one of those long canals when a potential catastrophes occurs. >> i was swimming down the canal in neck deep water. and he started coming out of sedation. >> reporter: the boy starts to come to. you realize you've got to re-administer the sedation you've got to put them out. >> it was very tricky. i had syringes floating around on the surface trying to grab ahold of them. >> reporter: so you literally grabbing this stuff in the water and trying to put it back in?

>> and try and get a needle on the syringe, get his leg up and do it one handed and get your syringes back in your dry tube. >> reporter: he would be forced to administer three more shots along the way. had you ever administered a shot to anyone? >> never. >> reporter: had you ever felt that isolated and responsible in your life before? >> never. the responsibility is huge. >> reporter: meanwhile in chamber three, there's a team of thai navy s.e.a.l.s, along with medics from the u.s. military anxiously awaiting mallinson and his special cargo. >> there was a line that would come up outta the water in chamber three. until that line would start to move, we absolutely had no idea. i think it was more nerve-racking when they said, hey. the line's movin'." and at that point, you know, five to ten minutes later somebody was comin' up. >> reporter: after what seemed like an eternity, mallinson emerges from the darkness with that first child in tow. >> everybody kinda just sighed and were like, "wow, it actually worked." >> are you absolutely sure? the kid's breathing? yup. kid -- kid is doin' fine. >> reporter: the young boy is

immediately tended to by medics. >> translator: the doctor would measure the oxygen level in the body, the kid's breathing, the pulse. >> reporter: he's then loaded onto a stretcher for the remaining half-mile extraction. >> it took more than 100 people to bring them to the entrance of the cave. >> reporter: but it won't be easy. they have to navigate the stretcher across extremely difficult terrain, over boulders and across steep cliffs. at one point they connect the boy to a series of zip-lines to make it easier to move him along. is this the actual litter that you used? or one of the types? >> absolutely, yes. >> reporter: staff sergeant sean hopper, a pararescueman from the u.s. air force showed us how one of those zip-line systems worked. >> i would do the hooking up. i would yell down to my next group and say, "hey, are you ready to receive? affirmative ready to receive." somebody would man this rope. >> reporter: to make sure the thing doesn't get away from you. >> correct. we want a nice slow traverse. >> reporter: after 16 days, the first boy is finally out. he's immediately rushed away

into a waiting ambulance. >> that is the first ambulance the whole world has been waiting to see this. we believe that the first boys from that cave are in that ambulance. >> reporter: describe that moment when the first boy came out of the cave. and you knew that you could do this. >> i think that everyone in the front line felt great. yes, big relief, yes. >> you're like, "okay, is this gonna happen a second time? is this gonna happen a third time?" i really hope that i don't get the bad news. and then it's like, "nope, child three's up. he's breathin'. he's well. >> translator: the third and the fourth came out at 7:40 and 7:50. today was very successful, more than we expected. >> so although we had a brief sense of happiness and euphoria after the end of the first day, that was tinged with the dread of knowing that we had to do this operation twice more. >> reporter: as the sun rises the next day over the doi nang non mountain, divers go to work

perfecting their escape plan. >> i began to kind of work how, you know, how to get through the awkward sections. in the lowest section of the cave, my back would be against the roof of the cave in my chest against the floor. i could actually hold the child off to one side and by rotating him round so that the cylinder he had on his chest was to the side of him, we could both slide through the lower sections without having to remove any diving cylinders. >> reporter: and by nightfall, four more boys trade the darkness of the cave for a starlit night. just minutes ago, we saw the seventh and eighth ambulances bringing the most precious cargo in all of thailand. but this is not mission accomplished. four boys and the coach are still sleeping inside the cave that night. >> after a success, there's a huge gap for complacency. everybody had to keep focused on what their task was, you know, to ensure that -- that errors weren't made. >> reporter: and the weather is about to take a dramatic turn for the worse. >> the pressure was really on now.

now actually the expectation was that we would get them all out. the chance of losing a single child would be catastrophic. >> reporter: the next day would bring a complication with one of the masks no one saw coming. >> it didn't fit him. we put it on him, really strapped down tight. we just couldn't get it to seal. >> reporter: stay with us. for my constipation, my doctor recommended i switch to miralax. stimulant laxatives forcefully stimulate the nerves in your colon. miralax is different. it works with the water in your body. unblocking your system naturally. miralax. now available in convenient

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>> reporter: jason mallinson is a man on a mission. thrust onto a global stage, and into a dank cave, he needs the rain gods to hold off one more day. >> were you growing nervous because of the storm coming? >> i think everybody was on edge because it had rained the night before. >> reporter: chris jewell is another unlikely hero. young and enthusiastic, jewel is taking part in his very first rescue mission.

>> so, the visibility throughout the whole operation was really, really poor. >> reporter: together with two other brits, collectively dubbed the "awesome foursome," they will attempt to finish off a dramatic three-day cave rescue as the world watches. >> these u.k. divers and the european divers, these were all by-name requests -- to come in and do this. >> reporter: they better hurry. heavy rains are threatening to scrap the plan. >> i mean, i think that not just my head, like, everybody's head was like, "hey, we're not gonna be able to continually execute the way we did on day one and day two, if these rains really start coming." >> reporter: the weather is one obstacle. the number of people that still need to come out of the cave -- another. four boys, one coach and four thai military members are still inside. >> on day number three, we had to bring out an extra person. so, in order to do this, jason mallinson swam through the final underwater section twice. >> i wish i'd never volunteered for it. to be honest, i knew the

visibility was going to be bad. >> they also understood there just was not any other option. if these kids are getting, you know, saved, it's gonna have to be them who does it. >> reporter: after pulling the soccer coach through the most dangerous part of the cave's flooded section in his first rescue today, mallinson hands him off to another diver and goes back to chamber nine, to grab the last boy. in chamber four, the final underwater section, chris jewell is headed -- to chamber three. he's got his hands full carrying a boy in one hand, a guideline with the other. unlike days one and two, the current is strong. >> so, it was moving one of the boys from my left hand to my right hand. i managed to let go of the guideline, which cave divers use to navigate in zero visibility. >> reporter: jewell makes a sweeping motion in an effort to find that guideline, but can't. the only lifeline he can find is electrical wire

installed by the support team earlier in the week. now jewell assumes that the electrical line will lead him toward the cave's exit, but in the stew of darkness and muck, he becomes hopelessly disoriented and heads the wrong way. >> i surfaced in a different section of the cave and i really didn't know where i was for several minutes. i got the boy out of the water, made him comfortable, took off my cave diving equipment and then i was able to walk around the chamber and recognize that i was back in chamber four. >> reporter: meanwhile, mallinson has issues of his own with the final rescuee. a 13-year-old nicknamed mark. >> the last child is there who is a really small child. too small in fact -- for the diving mask brought in for him. >> it didn't fit him. we put it on him, really strapped down tight so his nose was flattened against his face and there was a big gap under his chin. we just couldn't get it to seal. >> reporter: remember, a leaking seal means the boy could drown. so, with the clock ticking and

the final child already sedated, two divers in neck deep water have to think fast. they decide to use a different mask. it's not perfect either, but it might form a tight seal around the boy's face. >> it was so nervous for me because it was the different type of mask with this seal that you could dislodge sideway. i had to be so careful with him. >> you're freezing. you're shivering in the water. first face mask doesn't work because the boy's too small. the second one doesn't have a great seal. are you thinking, maybe we need to postpone this? >> we knew we didn't have any more time and we knew this was the last option. >> once you set off with that kid, it was a one way journey. you weren't going back to where they started. it was a case of getting him out. a bit brutal, but dead or alive. >> reporter: with no alternative and no communication available to bring in another mask, a decision needs to be made. >> i think it was my call, too, whether or not i was going to dive out with him or not. and i just made the call.

>> reporter: the call is made. the dive begins. but as soon as he's underway with his precious cargo -- another hazard. >> and by this time, the visibility had deteriorated where you could hardly see your hand in front of your face. it was feeling the line all the way out. >> reporter: low visibility means slow going. mallinson is laser focused on keeping that mask on the boy's face and can't afford to have the boy accidentally bang his head against the wall. >> and because the visibility was so bad, i know i couldn't really stop his head banging against the wall because i couldn't see his face or his head. so, i developed a technique where i'd pull him in really tight with his head just down here. and i'd extend my head over the top of his so my head hit the wall first and it protected his head. >> how many times do you think you hit your head that third day? >> dozens? dozens. >> reporter: to keep them alive -- mallinson knows he must keep moving. >> that was one of the

instructions dr. harry gave us. he said, "no matter what happens, get them out as fast as possible. hypothermia is going to be a big issue here." >> reporter: the only guy not moving at the moment is chris jewell. remember, he's the diver trying to figure out his next move after going deeper into the cave by mistake. when we return. ♪ ♪ ♪ ♪ buy one take one is back, at olive garden. starting at just $12.99. enjoy one of your favorites with us.

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>> reporter: british diver chris jewell has lost his way -- with precious cargo. while carrying a boy in one hand, he's dropped the guideline. disoriented, he finds himself meandering deeper back into the cave -- in chamber four. >> my concern, at this point,

was the boy was transporting. he'd now been -- we'd now been bringing him out for quite a while and i was concerned that his body temperature was getting kind of low. >> reporter: on his way out, australian rescue diver, doctor richard harris, or "harry" to his friends, comes across jewell and the boy. >> and harry was able to take the boy from me and dive ahead. and i followed him closely behind just making sure that he didn't have any problems in the way i had problems. >> reporter: harris and jewell make it out safely with the boy. they've been passed along the way in the cave by british diver jason mallinson who had emerged from the salty water with mark a few minutes earlier. incredibly -- the entire team is out. it's the end of the 18-day drama that captivated the world. the divers scramble through the first grand chamber of the cave to the applause of hundreds of rescue workers. >> literally, you were applauded the whole way through? >> we go out to do, you know, help people with the skills we've got. that's what we did. we were happy about that.

it's nice to be applauded and stuff, but it's not what we're after. >> reporter: but still, on the way out the cave, the three thai navy s.e.a.l.s and the thai doctor who spent over a week with the boys. and now there is a final crisis -- the pumps stopped and then the pipes cracked. water begins to flood the cave once again. there are still dozens of rescuers inside. >> our direction to them was, "start packin' up your stuff, you gotta get out of there." not everybody back there had an air source. >> reporter: the four thai divers make it out in the nick of time. after it's all over, jason mallinson allows himself just a hint of a smile. >> it does have to feel pretty good. >> yeah it felt good. yeah, we never envisioned it would be completely successful. we're just so glad it was. >> reporter: whisked immediately into quarantine, the boys are

unaware of their global superstar status. >> there was really no sense, i think, amongst the boys that there would be this enormous, you know ,media frenzy. >> all 12 players and their coach have made it out. >> it's a miracle. >> it's now mission accomplished. >> every member of that soccer team in thailand now free. >> reporter: every step of their recovery is monitored closely by doctors and the world. >> reporter: dr. paul auerbach, not part of their care team, but riveted by their story, is an expert in emergency medicine. >> when the boys got to the hospital, they were malnourished. they were weak. >> reporter: from their beds, the boys and their coach dispatch messages of gratitude. they flex their recovering muscles and share their food fantasies. 14-year-old adul craves the colonel's favorite. one of the only boys with a

smattering of english, adul was the boy who communicated with the two british divers who discovered them. >> now, i am very fine. i am, very. thank you for helping me. thank you so much. >> reporter: doctors delay revealing the most heartbreaking part of the rescue operation. >> they kept the news of the death of the navy s.e.a.l. from the boys in the early days of recuperation in hospital, because they didn't want to further upset them. >> reporter: a photograph of all the navy seal was put up in their ward. they stood for a minute of silence and respect. finally, after a little over a week, the boys and their coach say goodbye to their caregivers. >> reporter: this boy, overcome by tears.

t is time to face the world. trading their hospital gowns for their sports jerseys. they show off their soccer moves, still intact, and meet the international media. >> my name is chanin vibulrungruang. >> reporter: the questions are prescreened by the thai government. it says to avoid topics that might re-traumatize the boys. >> the thai government has been really really protective of these boys. their mental health. the boys actually spoke more freely than i think the authorities thought they would. they were happy to be out. happy to be celebrated. >> reporter: they apologized to their parents for ever going into the cave in the first place. >> it was nice to just see the gratitude they survived something they probably shouldn't have survived. >> reporter: then finally, more than three weeks after leaving home on that fateful adventure, it's time for homecomings.

at the small baptist church where he spent most of his childhood, adul gets that kfc. 17-year-old night is doused with water, a northern thai tradition to call his mind back after such a long time away. >> physically, the boys and the coach came through this remarkably well. emotionally, it'll take a while to completely sort this out. they'll need to be closely served for any signs of ng bact. they are celebrities. they're heroes, and it's not a normal situation to be in that environment. >> reporter: their rescuers are making headlines as well. earlier this week, british and australian divers were honored

by their governments. >> on behalf of all australians, we thank you and we salute you. >> the whole world and, particularly, the thai government, hailed you as heroes. is that how you feel? >> not really. we don't really go out and covet that sort of thing. there were other people on the -- on that rescue that were heroes. i think the four navy s.e.a.l.s that went into the chamber and stayed with them right to the end, i think they're probably a better classification of heroes. >> very, very happy and impressed. >> are you a hero? >> no, no, no. >> reporter: but the incident commander, narongsak osatanakorn, respectfully disagrees. >> everyone is a hero. >> everybody is a hero. how many people total were involved in this operation? >> i think, every day, we had almost 2,000 people. >> we were simply part of a big international team. we played a part, but we couldn't have done it without all the efforts of everybody else involved in the rescue. >> translator: the operation is

like a jigsaw puzzle picture. every piece of it is important. >> looking back on it, can you believe that you actually accomplished this mission? >> it's a surreal type thing. we look back on it now and think, "wow. this is -- this is the stuff of movies." >> all of us were doubtful. but we still kept faith, and we still kept hope. because of human fortitude, human perseverance, combined with professionalism, has showed us that, you know, almost anything is -- is achievable. >> reporter: next -- the boys begin their new lives. it's willingham, edge of the box, willingham shoots... goooooooaaaaaaaallllllll!

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who people locally believe inhabits the cave. the idea is if she's happy she will smile favorably and help a good outcome. >> reporter: an outcome not lost on any of those gathered at a temple this week to give thanks to buddha for the boys safe rescue and watch them take their first steps to become novice monks. one boy is not being ordained because he is not buddhist. the boys then enter a monastery to spend nine days praying the amount of time the they were trapped in the cave before being discovered. >> the boys will go and spend some time in a monastery giving thanks for their safe rescue and hopefully will also mean that they can clear their minds of any anguish and sadness or anxiety that they have about the time that they spent inside the cave.

>> reporter: and at the entrance to the cave where that remarkable drama gripped the world for nearly three weeks, cleanup is under way. the brigades of cave divers, troops, and media now replaced by cleanup crews. but the deliverance that the world witnessed at tham luang cave is a memory that will never be forgotten. >> translator: finally, everyone is happy. the people of thailand are happy, the people of the world are happy, so i'd consider this an operation that the world will never forget. >> reporter: whether it was the spirit of the princess that held the rains off and kept those water pumps going until the remarkable rescue team got the last boy out. we may never know. >> with all of the boys rescued there's a simple feeling for the locals all their prayers were answered. that princess who they beseeched to help she did indeed. >> there was absolutely supernatural intervention at

some level to have this succeed whether people were religious or not with the amount of people praying and everybody all around the world watching something bigger was at work here. >> and we note tonight that at some point after those boys and their coach leave the monastery, they have plans to meet the divers who saved them. only this time, face-to-face without those masks in between them. i'm david muir. for amy and all of us here at "20/20," thanks for watching on a friday night. have a good evening and a great weekend. breaking news, a family is missing and fire burning in

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