MAE SAI, Thailand -- Thai authorities overseeing the rescue operation for 12 boys and their soccer coach trapped in a flooded cave in the country's north said they have a "limited amount of time" to get them out, as they raced Friday against worsening weather and lowered oxygen levels in the underground complex.
The massive operation inside and around Tham Luang Nang Non cave in Chiang Rai province suffered its first fatality Friday when a former Thai navy SEAL passed out underwater on an overnight mission and was unable to be revived.
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"We can no longer wait for all conditions (to be ready) because circumstances are pressuring us," Thai SEAL commander Arpakorn Yookongkaew told a news conference. "We originally thought the boys can stay safe inside the cave for quite some time but circumstances have changed. We have limited amount of time."
The oxygen levels inside the cave were getting lower because of all the workers inside, and authorities on Friday were trying to install a 3-mile-long oxygen tube to pump in air, CBS News correspondent Ben Tracy reports.
A senior army commander, Maj. Gen. Chalongchai Chaiyakam, said that the most pressing mission was to provide the oxygen line to reach the kids, who are stuck deep in the complex but are being looked after by four SEALs, including a medic. He said the oxygen line was also tied to a telephone line that would provide a channel of communication for the team.
The boys, aged 11-16, and their 25-year-old coach went exploring in the cave after a soccer game June 23. Monsoon flooding cut off their escape and prevented rescuers from finding them for almost 10 days as the only way to reach them was by navigating a series of dark and tight passageways filled with muddy water and strong currents.
Authorities have been racing to pump out water from the cave before more storms hit the region in the coming days and send water levels rising again. Due to high water levels, the only way for the boys to get out of the cave would be by diving, something cave rescue experts warn is extremely dangerous, even for those with experience. Authorities were trying to drain the flood waters to a level where the boys would not have to dive and could swim out with their heads above water, Tracy reports, but there were worries that even if the water levels were lowered, the boys would not have the endurance to make the trip.
Friday's death of the former SEAL underscores the risks of diving. The diver was working in a volunteer capacity and died during an overnight mission in which he was placing oxygen canisters along the route divers must take to get to the children.
The strategically placed canisters would allow divers to stay under water for longer during the approximately five hour trip to reach the stranded team. While underwater, the rescuer passed out and efforts to resuscitate him failed.
The governor has said the 13 boys may not be extracted at the same time, depending on their condition. The boys were reportedly weak but for the most part physically healthy. They had been practicing wearing diving masks and breathing, in preparation for the possibility of diving.
Cave rescue experts have said it could be safest to simply supply the boys where they are and wait for the flooding to subside. That could take months, however, given that Thailand's rainy season typically lasts through October. And without proper oxygen levels, staying put could also prove deadly.
Meanwhile on Friday, FIFA, the organizers of the World Cup, sent a letter to the president of the Football Association of Thailand offering their "deepest sympathies and support" to the families of young soccer players and their coach.
The letter, signed by FIFA President Gianni Infantino, invited the team to the World Cup final in Russia, should they be rescued in time and be healthy enough to travel.
It said that the team's appearance at the final would "undoubtedly be a wonderful moment of communion and celebration."
The boys have asked the navy SEALs taking care of them in the cave for details about what has happened in the World Cup since they got trapped on June 23.