In the end it was a textbook rescue operation. Divers managed to carry, pull and at times swim the 12 young Wild Boars footballers and their coach along more than two miles of flooded and cramped tunnels in the Tham Luang cave complex, as billions of people around the world watched.
But briefings by Thai officials and interviews with six Australian, American, Chinese and Thai divers involved in the operation have revealed extensive details of a plan some were unsure could work, even after it started on Sunday morning.
“At the end, after we managed to get everyone out, we were just sitting there shaking our heads,” said Claus Rasmussen, a Danish diver who helped to execute the rescue. “We have no idea how this worked or why, but it did.”
The plan to ferry the boys out accompanied by two expert divers, and escorted by a daisy chain of support workers, started to firm up as the most likely option on the evening of Thursday 5 July, said Ruengrit Changkwanyuen, a diver from Thailand who helped coordinate the diving teams – and to carry the first two boys to a field hospital when they emerged on Sunday.
By then the boys and their coach had been trapped for more than 13 days, after a fun excursion into the cave turned into a nightmare when flash floods cut off their exit. They were not discovered until 2 July, when John Volanthen, a Briton, found them huddled on a muddy slope nearly two miles inside the cave.
By the time the rescue plan was formed, more than 1m cubic metres of water had been drained from the cave using pumps, but the boys would still be underwater, tethered to a diver, for much of the first 1.7km of the journey. For the last 1.5km, they would be on stretchers attached to a pulley system, guided home by more than 100 rescuers fanned out along the path.
Changkwanyuen helped to arrange the delivery of equipment including small wetsuits, full-face scuba masks and underwater lights, ordering huge supplies in case some of it failed. Anyone trying to buy a scuba mask in Thailand this week would be disappointed, he said. “Basically every full-face mask in the country is here.”
Authorities had been trying to avoid bringing the boys out through water, which Rasmussen had earlier said was “definitely the scariest option”.
But what was the alternative? Even keeping the boys in the cave chamber until January was looking increasingly risky, after medics reported that oxygen levels had depleted to 15% and that the boys could fall into a coma if it fell to 12%.
“That made us worry a lot,” Apakorn Youkongkaew, a rear admiral in the Thai navy, said. “It was hard to fight nature. What would we do if the oxygen kept decreasing?”
Preventing disease in the dank environment would also have become increasingly difficult. “It is very likely that infections would have started setting in, and the boys would have deteriorated a lot faster than they already were,” said Rasmussen.
Another plan, to drill approximately 600 metres into the boys’ chamber from the thicket of jungle above, was also foundering. Engineers could not figure out where to drill. “It was like finding a needle in an ocean,” said Youkongkaew.
Monsoon rain predicted for the morning of Saturday 7 July might have flooded the cave, making an extraction impossible. When it didn’t come, rescuers knew they had to go for it.
“We had enough people to run the teams, the environment was right, we had a window with the weather,” said Rasmussen. “We thought, this is going to be the best option we’re going to get.”
Inside the cave on Sunday morning, unaware of the dangers ahead, the boys were excited, says Changkwanyuen. “They were like, ‘oh wow, I’m going to go diving’,” he said.
However, the rescuers were wracked with anxiety. “There were way too many unknowns,” said Rasmussen.
Chanin Wiboonrungrueng, nicknamed Titan, 11, the youngest of the group was the focus of most concern. Rescuers sourced the smallest scuba mask they could find – but had to make it even smaller.
When Wiboonrungrueng started his journey out of the cave on Tuesday, they were still unsure whether the mask’s seal would hold. “We feared that it wouldn’t fit him properly. That was the biggest worry,” Rasmussen said.
Rescuers planned to start with the strongest boy, said Changkwanyuen. “But the Australian doctor Richard Harris evaluated the boys and said everyone was equally strong – so they picked among themselves to see who would come out first,” he said.
Thai officials said this week that the ultimate decision was made by the boys’ coach, Ekaphol Chantawong. “The coach selected. He wrote the order down: 1, 2, 3, 4, 5,” said Narongsak Osatanakorn, the head of the joint command centre coordinating the operation.
The boys were given anti-anxiety medication. Rescuers would not comment on its strength, saying it was a matter for the Thai government. “If they were anxious, they could squirm,” Youkongkaew said. “Some were conscious and some slept. There was no problem.”
Rasmussen was stationed at an area known as Pattaya Beach, about 3km inside the cave and the longest dry patch between the boys’ chamber and “chamber three” – a forward operating base for the rescue operation.
On each of the three mornings of the rescue, he would make the arduous two-hour trip to his designated area with two other divers, train his eyes on the dark water beyond him, and wait.
At about 2.30pm on Sunday, a diver emerged holding the first of the boys.
“As a team we were working together to put them in a stretcher as soon as they arrived on Pattaya Beach [a dry part of the cave complex] and getting them back into the water as fast as we possibly could,” he said.
“I was crouching, crawling, walking through water and over rocks, keeping the kids in the stretcher so they could be protected through all of this,” he said.
Navigating the steep, wet and muddy path in his section took about 20 minutes. Rasmussen worried about every second, aware that the boys would be in cold water for two hours, risking their core body temperatures falling to dangerous lows.
“Time was of the essence for us,” he said. “If we fell or were slow it would interrupt not just the flow of what’s happening but the whole rescue.”
Every diver interviewed said it was only at the end of the first day that they started to believe they might succeed. “It was only when we made it out on Sunday and heard the kids were all very good and on their way to Chiang Rai hospital, we thought, fuck, this might actually work,” said Rasmussen.
The operation became more efficient with each day, but he said the slightest hitch – such as heavy rain – might have condemned some of the boys to staying inside the cave. “We were still ready to back out completely on Monday night,” Rasmussen said.
About three hours after the last boys and Chantawong made it out on Tuesday, with the last navy personnel leaving the cave, the entire rescue system suddenly collapsed.
“All of a sudden a water pipe burst and the main pump stopped working,” Changkwanyuen said. “We really had to run from the third chamber to the entrance because the water level was rising very quickly – like 50cm every 10 minutes.”
Australian divers in chamber three described hearing screams further up the tunnel, then seeing a rush of head lamps coming towards them.
“It was like a movie scene, everything was collapsing,” Changkwanyuen said. “It was one of those acts of God. The cave spirit didn’t want us in there any more. It was saying, ‘I’ve had enough of you guys, it’s time to leave.’”
Rasmussen does not have a spiritual explanation, but agrees the timing was eerie. “That everything breaks down as soon as everybody’s safe? It’s just weird,” he said.
The cave is now empty again, flooded and inaccessible. Divers will need to return in five months to collect their equipment.
Rasmussen said he would seek out two particular boulders that had bothered him. “I’m going to find them and spit on them,” he said. “They spent the week banging my toes and head.”
