NATIONAL HARBOR, Md. -- Air Force Maj. Charles Hodges and Master Sgt. Derek Anderson didn't sugarcoat the facts.

They were on foreign soil, serving in an advisory role after being summoned on short notice to Thailand to assist with a treacherous situation grabbing headlines around the world: 12 Thai boys and their soccer coach, trapped deep in a maze of caves amid rising waters. The Thai authorities wanted a no-risk rescue solution but, as the airmen saw it, they just didn't have one.

"It's ... zero visibility, it's cold, and it's far, far back into a cave," Anderson said. "It was never any guarantees, and I remember [Hodges] saying specifically, maybe a 60 percent chance of survival … We were completely honest when we were briefing some of the Thai leadership that we were expecting casualties, just because, even though we did as much mission planning and rehearsals, everything that we could possibly do, nothing has been done like this before."

Put starkly, they had come up with a plan that they believed would result in three to five of the soccer team members not surviving the rescue. But the alternative, they believed, was far worse.

The boys, aged 11 to 17, and their 25-year-old coach had become trapped in the cave June 23 after entering to explore and having their exit cut off by rising waters. With a heavy summer rain season set to start as June turned into July, the multinational rescue team either had to attempt a risky extraction or leave the boys where they sat for a period of months, shuttling food in as they could. The airmen believed that option would prove fatal for all.

"You've got to do something because, if you don't do something now, the decision will be made for you, and it will be a very negative decision," said Hodges, the mission commander for the rescue, who is assigned to the 320th Special Tactics Squadron, out of the 353rd Special Operations Group, based in Kadena, Japan.

Hodges and Anderson, a pararescueman and team lead for the mission, spoke to reporters at the Air Force Association conference this month near Washington, D.C., where they were recognized by Air Force Chief of Staff Gen. David Goldfein for their work in the rescue.

The team from the 320th got the call on the morning of June 27. By then, said Hodges, they'd already seen headlines about the crisis unfolding in the Tham Luang Nang Non cave system in Thailand's Chiang Rai province. By that evening, the team was on a C-130 transport, bound for Thailand.

In addition to being the Air Force's only special operations rescue capability in the Indo-Pacific region, Hodges said the 320th had built-in capabilities suited for rescues in extreme environments, including mountains, jungles and underwater, with combat diving skills. They delayed the flight to Thailand, they said, in order to bring on one member of the unit who just happened to be an expert cave diver.

But for a rescue attempt like this, with children trapped deep in an uncharted maze of caves, their condition unknown, there was no roadmap.

The airmen, in their advisory capacity, knew they had to attempt to map and label the caves. They started with Chamber One, the cave's entrance, and ultimately determined, with the aid of experts familiar with the cave system and combat divers, that the soccer team was trapped in Chamber Nine.

Then it became a question of how to reach them. The Air Force team gamed out a plan to drill down through the caves to reach the trapped teens and establish proof of life. This plan seemed to be the option of choice, Hodges said, until they realized that they would have to work through 200 meters of limestone from any direction to make it into Chamber Nine.

Then, they considered the possibility of using an industrial pump system to lower the water levels in the caves to allow the soccer players to exit.

"Who is really good at putting pumps in the ground and sucking out massive amounts of liquid? Petroleum companies," Hodges said.

They got as far as communicating with Chevron executives out of Bangkok before abandoning the option as too complex in light of the unpredictable cave conditions and water levels.

There was one option left: assembling a dive team to reach the trapped players. It would involve staging oxygen tanks along the route, lining up a rope system to guide rescuers, and actually drugging the players with the sedative Ketamine so they could be guided out on stretchers affixed with breathing apparatus. It was risky and technical. It required precision.

The bones of the plan were established by Anderson, Hodges said. The Air Force team met with the Thai Navy SEALs who were leading the effort and merged strategies, adapting elements of each group's plan.

The pressure, from within and without, was intense. But the airmen said they worked hard to keep mission first, even as frantic volunteers and onlookers swarmed at the entrance of the cave.

"Before we ever left, we briefed our guys and said we've all got kids, we're going to be emotionally attached to this," Hodges said. "We've got to do our best to remain emotionally invested but, at the same time, emotionally detached, so we can make decisions based off of logic and not decisions based off of feelings. ... I think it was helpful for us to come in as those advisers and have an outside perspective, and it was much easier for us to tell the senior leaders that, 'These are your choices. If you don't make this choice, then other choices will be made for you by default.' "

Before the first rescuer entered the cave system, the airmen said they insisted on an exhaustive mission rehearsal, in which the cave chambers were drawn out using ropes laid on the ground and each member of the rescue party had to replicate his movements as closely as possible, start to finish. This piece of Air Force standard operating procedure seemed pedantic to some, but ultimately revealed some planning oversights that divers were able to remedy, the airmen said.

By the time the rescue attempt kicked off on July 8, the party of 13 had been trapped in the caves for more than two weeks, two-and-a-half miles from the entrance. One Thai Navy SEAL, Saman Kunan, had already tragically died of asphyxiation while delivering supplies into the cave.

The rescue would take two days, slowed by extreme caution as Thai rescue divers navigated through narrow passageways and through black, silty water.

"It wasn't an issue of visibility; the visibility was always going to be bad," Hodges said. "They were kicking up so much silt that the concern was mud getting inside the regulators. Because the guy at the very front, he would start -- the guy that would come behind him, by the time he got out of the cave, his regulator was malfunctioning because there was so much mud inside his regulator."

The boys began to emerge from the cave the same day, each extraction taking grueling hours. The first day brought four boys to the surface; the second, another four; and the third, the final four boys and their coach.

In all, 18 divers were involved with the ultimate rescue effort, and Anderson and Hodges said they weren't ready to celebrate until the last rescuer had emerged in Chamber One. Everyone, rescuers and rescued, came out of the cave alive.

Then, sheer, raw relief.

"The actual core group of rescuers, we were all kind of exhausted, but just kind of in awe that we pulled this off over a three-day period," Anderson said. "Everybody was pretty quiet, just rinsing off our gear. The very next day, the hotel had a dinner for us and we were able to relax a little bit, take in what had happened."

As unlikely as a future cave rescue in the same conditions is, the Air Force is compiling lessons learned from the effort, Hodges and Anderson said.

As they recounted the saga, some three months later, disbelief still tinges their voices.

"I don't know if I'll ever have something like this again in my career," Anderson said. "I hope not. The outcome might be different."

-- Hope Hodge Seck can be reached at hope.seck@military.com. Follow her on Twitter at @HopeSeck.