MAE SAI, Thailand – Authorities were preparing Monday to resume the urgent, dangerous operation of extracting a youth soccer team from a flooded cave in Thailand a day after four boys were rescued and as rain threatened to raise water levels inside the cave again.
A heavy but brief downpour hit the area Monday morning, but it was unclear how the rain affected the conditions inside the cave where the 12 boys and their coach were stranded by the high water more than two weeks. New oxygen tanks were being placed in the cave before the second stage of the rescue effort began.
Extracting everyone from the cave could take up four days, but Sunday's success raised hopes that could be done.
Interior Minister Anupong Paojinda said the same divers who took part in Sunday's rescue will return to extricate the others as they know the cave conditions and what to do. He said the boys rescued Sunday were strong and safe but needed to undergo medical checks.
Thai Prime Minister Prayuth Chan-ocha was scheduled to visit the site later Monday, after first traveling south to Phuket, where a boat capsizing resulted in 42 deaths, mostly tourists from China.
"The operation went much better than expected," Chiang Rai acting Gov. Narongsak Osatanakorn, who is overseeing the mission, said Sunday night.
He told reporters the four rescued boys were taken to the hospital in the town of Chiang Rai, the provincial capital, for evaluation, and the next phase of the operation would resume after about 10-20 hours.
Narongsak said 13 foreign divers and five Thai navy SEALs took part in the key leg of the rescue: taking the boys from where they have been sheltering and through dark, tight and twisting passageways filled with muddy water and strong currents.
Two divers accompanied each of the boys, all of whom have been learning to dive only since July 2, when the first searchers found them.
Cave rescue experts consider an underwater escape to be a last resort, especially with people untrained in diving.
The death Friday of a former Thai navy SEAL, Saman Gunan, underscored the risks. The diver, the first fatality of the rescue effort, was working in a volunteer capacity and died on a mission to place oxygen canisters along the route., necessary for divers to safely travel the five to six hour route to where the boys are.
Narongsak said ahead of the rescue dive that recent mild weather and falling water levels had created optimal conditions for an underwater evacuation. Those conditions won't last if the rain resumes, he said.
After the four boys were removed from the cave, heavy rain started falling.
The potential for rising water and the dwindling oxygen levels added to the urgency of getting the team out. Efforts to pump water out of the cave have been set back by heavy downpours.
Narongsak said that experts told him new rain could shrink the unflooded space where the boys are sheltering to just 10 square meters (108 square feet).
On Sunday night, Thai navy SEALs posted a celebratory note on their Facebook page, saying: "Have sweet dreams everyone. Good night. Hooyah."
The boys and their coach, whose team is known as the Wild Boars, became stranded when they were exploring the cave after a practice game on June 23.
Monsoon flooding cut off their escape route and prevented rescuers from finding them for almost 10 days.
The ordeal has riveted Thailand and captured the world's attention. The search and rescue operation has involved dozens of international experts and rescuers, including a U.S. military team.
Elon Musk's Space X rocket company is testing a "kid-sized submarine" that could be sent to help boys trapped in a flooded Thailand cave.
Musk posted videos on Twitter of the aluminum sub being tested at a swimming pool Sunday midafternoon California time. If the tests were successful, the sub was to be placed on a 17-hour flight to Thailand.
A spokesman for Musk's Boring Co. tunneling unit, which has four engineers at the cave, has said Thai officials requested the device, which could potentially help the children through narrow, flooded cave passageways. However, it is unclear if the device is part of any current rescue plans.
President Donald Trump tweeted Sunday: "The U.S. is working very closely with the Government of Thailand to help get all of the children out of the cave and to safety. Very brave and talented people!"