A former Navy Seal has died while trying to help rescue the 12 boys and their soccer coach who have been trapped inside of a cave in Thailand for nearly two weeks.

According to Commander Arpakorn Yookongkaew, Saman Kunan died due to a lack of oxygen in one of the tunnels in the cave.

It's been reported that Mr Kunan was attempting to reach a cavern that had been set up as a commercial command centre 1.2 meters inside of the complex underground system. He was working as a volunteer for the mission and ran out of air when trying to return to the centre after placing oxygen tanks through the underground network.

Despite the best attempts of his diving partner to resuscitate Kunan, he was sadly declared dead.

Maintaining air supply to the boys inside of the cave has become the "top priority" for rescuers, who are trying to get the boys out during monsoon season. Due to the difficult weather conditions, which mean that the cave is in danger of flooding, it's possible that they may have to remain underground until October.

The oxygen levels inside of the chamber are now down to 15 per cent, while normal oxygen levels are usually around 21 per cent.

Deputy army commander, Chalongchai Chaiyakham, said he was unsure how long the boys could survive in such conditions.

A huge operation is now underway in the Tham Luang Nang Non cave complex, in Chiang Rai, northern Thailand. There are currently dozens of Navy Seals and international experts at the site, and all of them are working together to find the quickest - and safest - way of getting the boys out of trouble.

One proposition that has been suggested by the team is to fit the boys with full-face oxygen masks and accompany them on the long, dangerous swim through the complex tunnels system. However, as the death of Mr Kunan shows, this is an extremely risky decision as the tunnels pose enough of a threat to kill even an experienced diver.

It's believed that the boys are physically weak after going days without food and, according to a doctors report, two of the boys and the coach are suffering through exhaustion through malnutrition.

In order to help the international rescue mission, a team of bird's nest collectors from southern Thailand have arrived and offered their skillset to the rescuers. The eight men collect edible nests from limestone cliffs and use them as ingredients for a Thai delicacy made from solidified bird spit that can sell for hundreds of pounds a kilo.

The group's leader, 49-year-old Abdulrawheep Khunraksa said: "One member in our team was watching (the rescue mission) on television and thought 'how can we help them?'.

"We thought that we might have the expertise to help since we have climbed to collect bird's nests for generations."

The team will now set off up the slopes in the hopes that they will find an alternative route into the cave.

Mr Kunan's death marks a tragic turn of events in the rescue mission. Hopefully, given the number of resources available to them, rescuers will be able to get the boys out safe and sound.

A former Navy Seal has died while trying to help rescue the 12 boys and their soccer coach who have been trapped inside of a cave in Thailand for nearly two weeks.

According to Commander Arpakorn Yookongkaew, Saman Kunan died due to a lack of oxygen in one of the tunnels in the cave.

It's been reported that Mr Kunan was attempting to reach a cavern that had been set up as a commercial command centre 1.2 meters inside of the complex underground system. He was working as a volunteer for the mission and ran out of air when trying to return to the centre after placing oxygen tanks through the underground network.

Despite the best attempts of his diving partner to resuscitate Kunan, he was sadly declared dead.

Maintaining air supply to the boys inside of the cave has become the "top priority" for rescuers, who are trying to get the boys out during monsoon season. Due to the difficult weather conditions, which mean that the cave is in danger of flooding, it's possible that they may have to remain underground until October.

The oxygen levels inside of the chamber are now down to 15 per cent, while normal oxygen levels are usually around 21 per cent.

Deputy army commander, Chalongchai Chaiyakham, said he was unsure how long the boys could survive in such conditions.

A huge operation is now underway in the Tham Luang Nang Non cave complex, in Chiang Rai, northern Thailand. There are currently dozens of Navy Seals and international experts at the site, and all of them are working together to find the quickest - and safest - way of getting the boys out of trouble.

One proposition that has been suggested by the team is to fit the boys with full-face oxygen masks and accompany them on the long, dangerous swim through the complex tunnels system. However, as the death of Mr Kunan shows, this is an extremely risky decision as the tunnels pose enough of a threat to kill even an experienced diver.

It's believed that the boys are physically weak after going days without food and, according to a doctors report, two of the boys and the coach are suffering through exhaustion through malnutrition.

In order to help the international rescue mission, a team of bird's nest collectors from southern Thailand have arrived and offered their skillset to the rescuers. The eight men collect edible nests from limestone cliffs and use them as ingredients for a Thai delicacy made from solidified bird spit that can sell for hundreds of pounds a kilo.

The group's leader, 49-year-old Abdulrawheep Khunraksa said: "One member in our team was watching (the rescue mission) on television and thought 'how can we help them?'.

"We thought that we might have the expertise to help since we have climbed to collect bird's nests for generations."

The team will now set off up the slopes in the hopes that they will find an alternative route into the cave.

Mr Kunan's death marks a tragic turn of events in the rescue mission. Hopefully, given the number of resources available to them, rescuers will be able to get the boys out safe and sound.