A rescue operation began Sunday to extract 12 boys and their football coach who have been trapped for more than two weeks in a cave in northern Thailand, the head of the mission said.
"Today is the D-day. The boys are ready to face any challenges," rescue chief Narongsak Osottanakorn told reporters near the cave site.
18 divers have been sent inside the cave and the 13 waiting to be rescued have been informed. It's being reported that the earliest the boys will come out is 9pm tonight local time.
The rescue began 10am local time, shortly after officials cleared the area surrounding the cave in readiness for the rescue operation.
Osottanakorn confirmed all 13 inside the cave are "really healthy". He said the families of those inside accept the rescue plans.
Authorities made the call to proceed with the rescue as dark monsoon rain clouds loomed over the mountainous north of the country early on Sunday, potentially heightening risks at the cave where rescuers were still waging a "war with water and time" to save the boys.
"Assessing the situation now, it is necessary to evacuate the area for the rescue operation," said Mae Sai police commander Komsan Sa-ardluan over a loudspeaker earlier today.
"Those unrelated to the rescue operation, please evacuate the area immediately."
Media have been cleared from the staging area around the cave complex.
The boys, aged between 11 and 16, went missing with the 25-year-old after soccer practice on June 23 after they set out to explore the Tham Luang cave complex in a forest park nearby the border with Myanmar.
Following a relatively dry spell, fresh torrential downpours could pose a setback to rescuers who have struggled to drain the Tham Luang cave complex in the northern province of Chiang Rai.
Weather.com forecast sustained thunderstorms lasting through Sunday and Monday, with further stormy weather expected for around the next two weeks.
Earlier the Chiang Rai provincial governor said conditions “were perfect” for a rescue. However, the rescues are highly unlikely to occur simultaneously.
It will likely take several days to free the boys, with reports they will be freed either one or two at a time.
'Conditions perfect'
Narongsak Osottanakorn, a former provincial governor leading the effort said the "ideal time" for a rescue could come in the next two or three days.
Rescuers have conceded that evacuating the boys is a race against time with monsoon rains expected to undo days of round-the-clock drainage of the deluged cave.
More than 100 exploratory holes have been bored - some shallow, but the longest 400 metres deep - into the mountainside in an attempt to open a second evacuation route and avoid forcing the boys into a dangerous dive through submerged tunnels.
"Now and in the next three or four days, the conditions are perfect (for evacuation) in terms of the water, the weather and the boys' health," Osottanakorn, the chief of the rescue operation told reporters.
"We have to make a clear decision on what we can do."
Rescuers have fed a kilometres-long air pipe into the cave to restore oxygen levels in the chamber where the team are sheltering, accompanied by medics and expert divers.
"When we're in a confined space if the oxygen drops to 12 per cent the human body starts to slow down and people can fall unconscious," Narongsak said.
"There's also carbon dioxide. If the oxygen levels are down and the carbon dioxide levels are up, then you can get too much carbon dioxide in your blood."
Heavy rains could make the water rise to the shelf where the children are sitting, reducing the area to "less than 10 square meters," he added, citing estimates from cave divers and experts.
Boys send notes of assurance to worried parents
Earlier on Saturday Thai Navy Seals published notes scrawled by the trapped footballers to their families, who are waiting for them agonisingly close-by outside the cave entrance.
The children urged relatives "not to worry" and asked for their favourite food once they are safely evacuated.
In one Pheerapat, nicknamed "Night", whose 16th birthday the group were celebrating in the cave when they became stuck on June 23, said:
"I love you, Dad, Mum and my sister. You don't need to be worried about me."
Meanwhile, the 25-year-old coach Ekkapol Chantawong, the only adult to accompany the boys into the cave, sent his "apologies" to their parents.
"To all the parents, all the kids are still fine. I promise to take the very best care of the kids," he said in a note given to divers on Friday.
"Thank you for all the moral support and I apologise to the parents."
The boys are being trained in the basics of diving in case the floodwaters force authorities into a sudden evacuation.
The rescue timeline
Here is how the rescue attempt has unfolded so far:
Saturday, June 23
The youngsters, aged between 11 and 16, and their 25-year-old coach enter the Tham Luang cave in northern Thailand during heavy rains after football practice.
They are reported missing by a mother after her son does not come home that night. Local officials find bicycles locked to a fence and shoes and football boots close to the entrance.
Sunday, June 24
Park officials and police find handprints and footprints believed to belong to the boys and think they likely retreated into the winding tunnels as they became hemmed in by rising floodwaters. Relatives start to keep a vigil outside the cave.
Monday, June 25
Thai Navy Seal divers enter the cave searching for the boys. Makeshift shrines are set up for parents to pray and make offerings, as heavy rains continue.
The boys are believed to have retreated further into the cave to an elevated air pocket called "Pattaya Beach".
Tuesday, June 26
Divers reach a T-junction several kilometres inside the cave but are forced back by rushing floodwaters that clog a narrow crevice near Pattaya Beach.
Wednesday, June 27
A team of more than 30 American military personnel from the US Pacific Command arrive, including pararescue and survival specialists. They are joined by three British diving experts who go into the cave's entrance but quickly retreat because of heavy flooding.
Thursday, June 28
The underwater rescue is temporarily halted because of the fast-moving floods inside the cave as downpours refuse to let up.
Water pumps are shipped in to drain the rising, murky floodwaters. Drones are dispatched to help find new chimneys.
Friday, June 29
Thailand's junta leader Prayut Chan-O-Cha visits the site and leads a meditation, jokes and cooks with relatives, asking them not to give up hope.
Saturday, June 30
A break in the bad weather allows divers to reach further inside the cave but they are still far away from where the boys are believed to be.
Sunday, July 1
Divers inch further into the cave, as an operating base is set up inside and hundreds of air tanks and other supplies are pulleyed in. Rescuers can now remain underground for longer.
Monday, July 2
A miracle, finally: the 12 boys and their coach are found alive late Monday evening about 400 metres beyond Pattaya Beach - which had become threatened by encroaching flood waters.
Crowds at the teeming rescue site cheer the good news and a nation breathes a sigh of relief. But attention turns to the difficult task of getting the boys out safely.
Tuesday, July 3
Much-needed food and medical supplies - including high-calorie gels and paracetamol - reach the boys as rescuers prepare for the possibility that they may remain in the cave for some time.
Wednesday, July 4
Officials say the group are being taught how to use diving masks and breathing apparatus. Authorities are pumping out water round-the-clock, aware of the bad weather forecast in the days ahead.
Thursday, July 5
In a sign of increased urgency, Thai rescuers say they may be prodded into a complex extraction if forecast rains hammer the mountainside. A team of bird's nest collectors scour the mountainside for openings.
Friday, July 6
Tragedy strikes: a diver helping to establish an airline to the boys dies after passing out while returning from the chamber.
Saman Gunan's death raises serious doubts over the safety of trying to bring them out through the cramped, waterlogged passageways.
Thailand's Navy Seal commander says oxygen levels inside have dropped. He warns the window of opportunity to free the youngsters is "limited", in the first official admission that they cannot wait out the monsoon underground.
Saturday, July 7
Rescue operation chief Narongsak Osottanakorn says it is "not suitable" to make the boys dive to safety yet.
A scrawled message emerges from the coach of the team, offering his "apologies" to their parents.
The head of the rescue mission says more than 100 chimneys are being drilled into the mountainside in a frantic bid to reach the boys.
