Monday was the second day of the relay extracting the boys from the cave complex. Timothy Ulrich explains how it's being done.

A team of nearly 100 divers has been working in the cave system. They have been guiding the boys through dark and submerged passageways towards the mouth of the Tham Luang cave system. Getting to and from where the boys are is an exhausting round trip, even for experienced divers. The process includes a mixture of walking, wading, climbing and diving along guide ropes already in place. Wearing full-face masks, which are easier for novice divers than traditional respirators, each boy is being accompanied by two divers, who also carry his air supply. The toughest part is about halfway out at a section named "T-Junction", which is so tight the divers have to take off their air tanks to get through. Beyond that, a cavern called Chamber 3 has been turned into a forward base for the divers. There the boys can rest before making the last, easier walk out to the entrance. They are then taken to a hospital in Chiang Rai.