Ekapol Chanthawong left his life in the monkhood and joined the Wild Boars as an assistant coach.

The head coach of the Thai soccer team spent the morning of June 23 preparing his young assistant for an important task: looking out for the boys by himself.

Nopparat Khanthavong, the 37-year-old head coach of the Moo Pa (Wild Boars) soccer team, had an appointment that morning. Ekapol Chanthawong, his assistant, was to take the younger boys to a soccer field nestled by the Doi Nang Non mountain range, a formation with numerous waterfalls and caves that straddles the Thai-Myanmar border.

"Make sure you ride your bicycle behind them when you are traveling around, so you can keep a lookout," he wrote in a Facebook message he shared with The Washington Post. Ekapol coaches the younger boys, so Nopparat told him to bring some of the boys from the older team for additional eyes.

"Take care," he wrote.

The hours that followed kicked off a chain of events that has riveted the world: a dramatic search and rescue that found the boys alive nine days later, huddled on a small, muddy patch surrounded by floodwaters. Attention has focused on the only adult, 25-year-old former monk Ekapol, and the role he has played in both their predicament and their survival.

Efforts underway to extract the boys have involved a swelling team of thousands of divers, engineers, military personnel and volunteers from all over the world - including Elon Musk's SpaceX - with no clear plan in sight. Diving, the most probable method, is seen as too risky for now given the boys' lack of swimming experience, pitch-black muddy waters through narrow passageways, and the death this week of a retired Thai Navy SEAL who was among those readying the cave for the boys' dive. Engineers have been searching for a way through the mountain's surface, hoping to drill down and reach them within the cave, but acknowledge it could take months and alter the cave's geography in the process.

As the rush to figure out how to rescue the group continues some have chided Ekapol for leading the team into the cave. A large warning sign at the cave's entrance raises the risk of entering so close to the monsoon season, they say, and he should have known better.

But for many in Thailand, Ekapol, who left his life in the monkhood three years ago and joined the Wild Boars as an assistant coach soon after, is an almost divine force, sent to protect the boys as they go through this ordeal. A widely shared cartoon drawing of Ekapol shows him sitting cross-legged, as a monk does in meditation, with 12 little wild boars in his arms.

According to rescue officials, he is among the weakest in the group, in part because he gave the boys his share of the limited food and water they had with them in the early days. He also taught the boys how to meditate and how to conserve as much energy as possible until they were found.

"If he didn't go with them, what would have happened to my child?" said the mother of Pornchai Khamluang, one of the boys in the cave, in an interview with a Thai television network. "When he comes out, we have to heal his heart. My dear Ek, I would never blame you."

Ekapol was an orphan who lost his parents at age 10, friends say. He then trained to be a monk but left the monastery to care for his ailing grandmother in Mae Sai in northern Thailand. There, he split his time between a working as a temple hand at a monastery and training the then newly-established Moo Pa team. He found kindred spirits in the boys, many of whom had grown up poor or were stateless ethnic minorities, common in this border area between Myanmar and Thailand.

"He loved them more than himself," said Joy Khampai, a longtime friend of Ekapol's who works at a coffee stand in the Mae Sai monastery. "He doesn't drink, he doesn't smoke. He was the kind of person who looked after himself and who taught the kids to do the same."

He helped Nopparat, the head coach, devise a system where the boys' passion for soccer would motivate them to excel academically. If they got certain grades in school, they would be rewarded with soccer gear, such as fresh studs for their cleats or a new pair of shorts. The two spent time looking for sponsors and used the Moo Pa team to prove to the boys that they could become something more than their small town would suggest - even professional athletes.

"He gave a lot of himself to them," Nopparat said. He would ferry the boys to and from home when their parents could not and took responsibility for them as if they were his own family.

He also kept the boys on a strict training schedule, according to physical education teachers at the school field where they practiced. That included biking across the hills that surround Mae Sai.

On that Saturday two weeks ago, Nopparat did not know where Ekapol would be bringing the young soccer team but thought it would be a learning experience for him to manage them on his own.

The older Wild Boars were having a match in the evening, he said, so he put his phone away. When he checked it at 7 p.m., there were at least 20 calls from worried parents, none of whose sons had come home. He frantically dialed Ekapol and a number of the boys in quick succession but reached only Songpol Kanthawong, a 13-year old member of the team whose mother picked him up after training. He told Nopparat that the team had gone exploring in the Tham Luang caves. The coach raced up there, only to find abandoned bicycles and bags at its entrance and water seeping out the muddy pathway.

"I screamed - 'Ek! Ek! Ek!,' " he said. "My body went completely cold."

Information had slowly started to come outabout the boys' nine-day ordeal before they were eventually found on Monday night, through letters and limited communication between the coach, the team and the rescuers who have been with them in a small cave chamber.

The rush of euphoria that ran through the town of Mae Sai and across the world when the group was found has settled into a grim reality that neither Ekapol nor the 12 in his care may see daylight for days or even weeks. Officials said Saturday that they have about a three- to four-day window in which conditions will be "most favorable" for the boys to attempt to dive out before monsoon rains hit and continue for months.

Urgent concerns include the amount of oxygen in the section of the cave that the group is taking refuge in, which had fallen below healthy levels. Officials are now limiting the number of rescue workers who can travel into the cave to reduce the amount of carbon dioxide that builds when they exhale. Rising water levels, too, could force a quick extraction, but authorities say the boys are not ready to make the dive.

Friends, meanwhile, grow worried for Ekapol. He had the boys' complete trust, and it is unlikely that they would have set off exploring in the cave's chambers without him.

"I know him, and I know he will blame himself," said Joy, his friend at the monastery.

On Saturday morning, the Thai Navy posted photos of letters that the group had written to their family and the outside world. Ekapol's, scribbled on a yellow-stained piece of paper, torn out from a notebook, was brief, but included a promise and an apology.

"I promise to take the very best care of the kids," he wrote. "I want to say thanks for all the support, and I want to apologize."