Plans called for the boys to be placed in ambulances and given medical assessments.
The entire operation to rescue all 13 could last two to four days, depending on weather and water conditions, said army Maj.
Meanwhile, rescuers have a dwindling window of opportunity, with forecasters predicting the return of heavy monsoon rains in the coming days, effectively sealing off the cave until October. Three workers were injured in a fall at the site on Saturday.
They were tearfully reunited with their weeping parents - who have kept a desperate two-week vigil at the cave entrance - before being taken to hospital.
Mongkhol Boonpiam's mother said last night she learned her son may have been rescued from social media.
Dark clouds and fog shrouded the area around the cave as a steady rain began falling in the early afternoon.
Who are the boys and their coach? A video from the Thai Navy SEAL Facebook page showed the group several kilometers inside the 10-kilometer (6-mile) cave network on a small wedge of dry ground. It was not immediately known if a USA diver was among them. 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. 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.
"At 10am (3am Irish time) 13 foreign divers went in to extract the children along with five Thai navy SEALs".
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After that, he worked in another top Michigan law firm and later founded a law firm of his own based in Troy, Michigan. The Associated Press has learned that Vice President Mike Pence has met with some of the candidates in recent days.
The announcement of US government involvement was sudden and this tweet is looked at as Trump's first public comment on the rescue mission. I've told Yod to get ready to take me out for fried chicken.
Boonpiam, a seventh-grader, was the first to emerge from the cave aided by divers because he was the worst off, local media reported.
On reading the letter Saturday evening, Chanin's father, Tanawut Viboonrungruang, said he felt a great sense of relief. One boy's note said: "I'm doing fine, but the air is a little cold, but don't worry".
Interesting Engineering will continue following this story and will update it as more information becomes available.
For the boys who can't swim, this 4km back to safety will likely take much longer. 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.
Thai officials said Friday that oxygen levels inside the cave plummeted to a risky 15% - shy of the US Department of Labor's Occupational Safety and Health Administration's "optimal range" of oxygen, which is between 19.5% and 23.5%.
On Friday, officials warned that oxygen levels in the cave dropped from 21% to 15%, complicating rescue efforts.
However, the boys and their coach are facing malnutrition, dehydration and other unknown ailments.