Elation at their discovery, however, quickly turned to anxiety. Capt. Anand Surawan, the deputy commander of the Thai Navy SEALs who was running an operational center in Tham Luang, suggested that the boys and their coach might have to stay in the cave for four months until the rainy season subsided.
Three Thai SEALs went missing during the operation for 23 hours, and when they finally reappeared, they were so weak from a lack of oxygen that they were rushed to the hospital.
Four days after the boys were found, Mr. Saman, the retired Navy SEAL who left his airport security job to volunteer, died as he was placing air tanks on an underwater supply route. His family declined an autopsy, but some Thai officials said that he ran out of air in his tanks. Others believe he succumbed to hypothermia.
“I’m very proud of him,” said Mr. Saman’s father, Wichai Gunan, a car mechanic. “He is a hero who did all he could to help the boys.”
Meanwhile, efforts to drain the cave, through pumps and a makeshift dam, began producing results. Crags and outcroppings emerged from the murk. The most waterlogged passage, which had taken five hours to navigate in the early going, could now be traversed in two hours with the help of guide ropes.
Racing the Rain to Start the Escape
By last weekend, the rescuers were eager to act. Rain was back in the forecast. The oxygen level where the boys were sheltering had dipped to 15 percent. At 12 percent, the air might turn deadly.
The operation kept shifting with each variable: the water, the air, the mud, even the mental and physical state of the young soccer players. Because the boys could not swim, they needed full-face masks into which a rich oxygen mix was pumped.
But the masks that the American team brought with them were sized for adults. So they tested the gear on volunteer children in a local swimming pool, and discovered that by pulling the five straps as tight as possible, they would work.
The 30-strong American team, which was integral to the planning, recommended that each child be confined in a flexible plastic cocoon, called a Sked, which is marketed as a rescue stretcher and is a standard part of the Air Force team’s gear.