Rescue divers have to navigate flooded passages, with some openings as small as 3 feet wide and 2 feet tall, to rescue 12 boys and their football coach who have been trapped for more than two weeks in a cave in Thailand.

Rescuers are bringing in supplies and equipment through the cave's main entrance. The shape shown here is the cross section of the cave at the entrance.

The rescue team has its base here in Chamber 3, a dry area about a third of a mile from the entrance. They are trying to run a communications line from here to the trapped team.

Starting at about a half-mile from the entrance, the cave dramatically narrows.

This is the cross-section of the cave at about three-quarters of a mile from the entrance.

It was here at Sam Yaek junction that divers first found the tunnel that led to the football team.

Authorities believe the football team fled rising waters here at Pattaya Beach, which has one of the smallest openings in the entire complex.

The divers found the 12 boys and their coach near this area, which is more than a mile and a half from the entrance.

While four of the boys were successfully evacuated Sunday, the rescuers face an increasingly dire situation. The boys have grown weak from falling oxygen levels in the chamber where they are trapped. One rescue diver died Friday when he ran out of air while underwater.

The cave system runs under a mountain range. Officials initially considered drilling as an approach for rescuing the boys, but that option has mostly been eliminated because getting the necessary drilling equipment up the mountain would be daunting and time-consuming.

The boys and their coach went into the cave after a practice on June 23 and were caught inside by rising floodwaters. They were trapped for 10 days before they were found.

The initial jubilation that the team had been found alive has given way to deep worry over the difficulty of getting them out. The July-to-November rainy season is a particularly dangerous time because rainfall can flood the cave with surging waters.

Officials are monitoring weather forecasts, with some expecting monsoon rains to arrive soon. The storms could slow the rescue effort and push water levels in the group's chamber even higher.

The boys, ages 11 to 16, and their 25-year-old football coach have begun basic training in how to make the journey through cramped and flooded passageways. None have ever used diving gear, and at least some of the boys don't know how to swim at all.

About 140 cave divers from Thailand and around the world are preparing for the rescue. The operation will require shepherding each person for hours through underwater passageways with few air pockets. THE NEW YORK TIMES