Transcript for Thai cave rescuers say they expected some kids to die during the mission: Part 1
thseow talking our Matt Gutman. Reportender a monssoain in northernand, in the deep-down-dark, a maje trap. After nine days of desperate G, the missing members of this bosoccer teaan their ach are fod,miraculously alive. From the shadows of the cave, indeliblemage, a roof hopemed around T Raise your hands. Thank youthank you. Ow you? 13. 3? Yeah. Brilliant people are coming. Many, many people. We are the. Absolute elation -- followed very quickly with, "Oh, wait a nd now we gotta get T kids out." Yeah, yeah.I am very happy. We are ppy too. Yes, thanyoh. Thk you. Oy. Where you come from? England, uk. Reporte tivers who find the boys, John volanthen and Rick Stanton, and ow divers son mallinn and Chris Jewell, belong to an britiscave divinte unique rescue skills. Thailand,hese volunteer working thout pay,om known to think a cod aboutheld go. I think it's human nature to know if you've gotility, then, course, you will. Reporter: The boys getfood, MREs a company. The military doctor them in the ca F their duration. When they got their energy back, the kiheerfully talked a about wherthey would go, what they would eat, their pla after they get out of the cave. R: A U.S. Air fo search and rescue team headed up by major charl sergeant rek anders, joins the effort. We came in bringing litary exptihen it comes to O control. When comes to, kind oreally long at a prle and finding what is the risk? Wh R willing T ac? Reporter: Every cave is filled with peril. A highlight by the death of one of the volunteers. A rescue Ver has died. The man who died was young.he was fit. Was a former Navy S.E.A.L. Rorter: Forr Thai Navy S.E., 38-year-oldman nanng out of tirement T help. On one of his dives, something terribly Ong. He is D unconsciou later dies. Itergeant Sam's moutiece fell off. He was TD it. Was trying tot spone, but D to the of the cave, there was no air to breathe.re very sa thole world llapsed. Felt like the whole world was collapsing? Yes. How did that affect moralmp? Obv, it made it little more somber. Mat a littleore serious. For the S.E.A.L.S, it caused them T re-double their ef everybody ry got to buness after. Reporter: What stands between the Bo haven't about LE and a hf unrground obstacle course of rochambers, lf flooded canals a fully subrged sens.thof those is 350 , E length seven olymc tools. And it's filled ke swimminin ffee. Physically could not see of your fe noatter how close put it to your face. Reporte advisors say theers tell them, bringing all the K of the floed cave ale will an imposs They'reeln' us this is the absolute W that can have R a rescue and it was pushing the envelop for what were comfoable with. They said, "This is incredlyifficult F U do, you know, M -- much less a child that's -- that's never." We always knew we could get them out, it whether W could get them out alive or not. Reporter: The Thais search for alrndrilling down through the limestone training the cathe end of the mooon season. But th is three or months away. The Thais are calling the shots. Bue Americans warn them, me is not onir side. We knew, at that point,t rains were com the Hain place is gonna become these certchambers a a of the cave get re-flooded. Reporter: As if the threat ofn't enoughmonitors in the cave de a drop in air quality. Translator: The other that helped us decide whether proceed with the or not decreasing aunt of ys and the assistaoach wereated. We that therwasn't a zero risk option.but we knethat theion of leavthe kids trer ive months was a bad option. Orter: Thebe preparations for mission imibing with a K piece of equipment, which the Americans ly. Iwas a positiressure full facemask that is a piece ofgo over your entire. To ensure that the Bo would be Abo breathe, and the full face mask W also ensure water couldn't get in tn air force officer shoots this cell phone video of theivers test the equipment going to use.them around with T full first underwate so erybody could what we we going to do. It wasn't a very depiction hat the reue divers would actually be a proof of cot, it rked. Reportehe strateg critical they run a drill, using les as pro for scuba tanks. Leverythingut in a big field. And we hadging pointset up T field. And Wead them walk through to make sur what we had ally rk in realife. Reporter: A sin ofcean the diffceife and death. Becau the last thing that weted was foone of the vers to show up at a staging point and think that there would be a repk there, a therwas nothing. Or even worse, there's a tank there th was. Reporter: Nowthat Ver the sile chillingsage to ththai govent that diving out is thio E at, where we could Gome of theout, orleave 'em there. And thera high chance that none of 'em sue." I said, "Man, this is our best shot." Id we've got an. It's a good plan. We think it might work. There's a chance some of kids might die. So, numbers wise, what was the probabilof success So, when I was asked that question by the governor, what I tom is, "I ink we can probabealistical S% 70% of thki I expect anywhere from three to ve to die inoperation." Reporte that is the he confronting thfficials -to save anythe boys, th have to risk losing some of them. He said, T's the best plaateard so far. Go ahead and stae going toffect this Reporte sad, before
This transcript has been automatically generated and may not be 100% accurate.