Navy SEAL diver DIES after running out of oxygen taking supplies to trapped Thai soccer team - revealing just how dangerous it will be to get children who can barely swim out of the cave system

• Twelve Thai boys and their football coach trapped in flooded cave for 12 days
• Thai Navy Seal Saman Kunan, 38, has died due to lack of oxygen in the tunnel 
• He was placing oxygen tanks around the cave at 1am Friday when he suffocated  
• Officials fear monsoonal rain could flood cave and trap team inside for months  

A former Thai Navy SEAL has died while trying to rescue the team of young footballers trapped in a cave in Thailand.

Saman Kunan, 37, died due to a lack of oxygen in the tunnel, said Commander Arpakorn Yookongkaew. 

Kunan was trying to reach a cavern set up as a command centre 1.2miles inside the cave system when he ran out of air at 2am local time.  

He was returning to the centre after placing oxygen tanks through the cave's underground network.

Yookongkaew said the rescuer was working in a volunteer capacity to help the 12 boys and their 25-year-old coach.

A diving partner tried to revive Kunan but was unsuccessful. 

His body has been sent to Suvarnabhumi airport in Bangkok and will be flown to his hometown in Roi Et for a royally-sponsored funeral, the Thai king announced.   

Kunan's final Facebook post was a picture of him proudly posing with his comrades at the mouth of the Than Luang cave.  

A huge operation is underway at the Tham Luang Nang Non cave complex, where dozens of Thai Navy SEALs and international experts are attempting to find a way to get the boys out.

Rescuers have been examining ways to rescue the boys, including fitting them with full-face oxygen masks and accompanying them on a long, dangerous swim through the tunnels.

However, the death of an experienced diver in the cave system underlines the inherent risks in attempting to move the boys, who are physically weak after days without food. 

It comes as officials warned the window of opportunity to free the youngsters is now 'limited' as the throng of soldiers, engineers, paramedics and other volunteers at the site swelled to 2,000.

Former Thai Navy SEAL Samarn Kunan, 37, (pictured) has died while trying to help rescue the young football team trapped in a cave in Thailand 

Kunan's final Facebook post was a picture of him proudly posing with his comrades at the mouth of the Than Luang cave

Kunan died due to a lack of oxygen in the tunnel.  He was trying to reach a cavern set up as a command centre 1.2miles inside the cave system when he ran out of air at 2am local time

Kunan was returning to the centre after placing oxygen tanks through the cave's underground network. This is the last known picture of the hero diver before he died

The mother of one of the trapped Thai boys breaks down as authorities announce the death of a former Thai Navy Seal diver during the ongoing rescue operation

'At first, we thought the children could stay for a long time... but now things have changed, we have a limited time,' Yookongkaew said, insisting morale remained strong despite the death of the diver.

'These accidents can happen sometimes to anyone in the field, but we will go ahead and keep working,' he told The Guardian.  

He added: 'We won't let his life be in vain. We will carry on.'

The SEAL unit said in a statement that Kunan's diving partner had found him unconscious in the water and tried to revive him but could not save his life. 

This morning, devastated Thai navy Seals paid tribute to their former colleague, describing him as a 'skilled and talented Seal and a triathlon athlete'. 

Their statement added: 'Even after he departed the Seal unit, he still kept in touch and maintained a tie with the rest of his former colleagues. 

'He always participated in the Seal activities until the last step of his life. Saman left us while working as a diver and in a time where all divers joining forces to complete the mission. His effort and determination will always remain the hearts of all divers.

'May you rest in peace and we will accomplish this mission as you had wished.'

It takes even the most experienced divers up to five hours to swim through jagged, narrow channels from where the boys are to safety outside.

Speaking to CNN on Wednesday, Cade Courtley, a former US Navy SEAL said bringing the children out through the flooded tunnels could be treacherous.

He says that even divers with considerable expertise have been 'climbing up, climbing through, going (through water with) zero visibility to finally get through the team. Now you're going to ask 11 to (16) year olds - some of whom cannot swim - to make that same journey for the first time breathing air underwater? I think that's a terrible mistake given some of the options we have.' 

Governor Narongsak has revealed that the three of the stranded children are also 'quite weak, weaker than the other boys'.   

Kunan was working in a volunteer capacity for the rescue mission. He is pictured here with fellow members of his team at the cave 

Kunan also posted this photo of his team planning the mission before going into the cave

Kunan proudly posted a number of photos that showed him with the Navy SEAL team

The level of oxygen in the cave has also become a cause for concern, with authorities revealing levels have dropped to 15 per cent. The usual level is 21 per cent. 

Narongsak Osatanakorn, the governor of Chiang Rai province, said that oxygen has been depleting inside the cave due to the presence of hundreds of rescue workers. 

Holes are being drilled in the jungle above the cave to try and increase air supply and about 30 oxygen tanks have also been released in their area. 

Authorities are also laying an air pipe from the entrance into the cave but said on Friday that another 1.7km of piping is needed. 

'The top priority today is to fill the air inside [where the boys are]' said deputy army commander Chalongchai Chaiyakham.   

'We've got to finish laying the air pipe today...With the air filled, the kids could stay for months.' 

The rescue mission's chief engineer is also looking into the possibility of rescuing the boys by drilling a hole where they are located. 

Rescuers initially believed that drilling was too dangerous due to the fact the boys and their coach are trapped in a small space.  

The official who is leading the rescue operation met with the boys' families last night.  

He maintained that the preferred rescue option was to escort the youngsters out with scuba divers with navy chaperones. 

It has not been decided whether the stronger or the weaker boys would be evacuated first, but the boys will come out one at a time. 

The governor would not confirm when the evacuation would begin but maintained the boys would only be brought out when the rescuers were 100 per cent sure they would be safe.

A huge operation is underway at the Tham Luang Nang Non cave complex, where dozens of Thai Navy SEALs and international experts are attempting to find a way to get the boys out

Officials have long feared the coming torrential rain would catastrophically flood the cave system in Chiang Rai and make rescue impossible

Meanwhile, fears are growing that time is running out to rescue the boys and their coach.

Officials have long feared the coming torrential rain would catastrophically flood the cave system in Chiang Rai and make rescue impossible.

Should the rains further flood the cave, as predicted, the team could be trapped in the cave for more than four months until waters recede.  

Provincial Governor Narongsak Osotthanakorn said the mission was 'a race against the water' that will flow in with the monsoon.

'Our biggest concern is the weather. We are calculating how much time we have if it rains, how many hours and days,' he said. 

Nineteen massive pumps are trying to lower the water levels - but this has been hampered after unregistered volunteers started pumping water back into the caves in the belief they were helping.

The boys aged 11 to 16 and the coach have practised wearing diving masks and Thai Navy Seals were told to prepare for a sudden evacuation.

However, the teams were still too weak to attempt to leave their flooded cave with two boys and the coach suffering from exhaustion. 

Water was accidentally pumped back into caves by volunteers amid desperate attempts to lower flooding levels in the sprawling underground network, it has emerged

A medical assessment found it was still too dangerous to try to move the youngsters, an unnamed source in the Thai Navy Seals told CNN.

Two boys and the 25-year-old coach are suffering with exhaustion through malnutrition, according to a new doctor's report.  

A team of bird's nest collectors from southern Thailand arrived to put their generations-old rock climbing skills to use to help with the rescue mission.

The eight men are Thai Muslims from Libong island in Trang province, where they climb limestone cliffs to collect the edible nests, a delicacy made from solidified bird spit that can go for hundreds of pounds per kilo.

'One member in our team was watching (the rescue mission) on television and thought 'how can we help them?',' team leader Abdulrawheep Khunraksa said.

'We thought that we might have the expertise to help since we have climbed to collect bird's nests for generations,' the 49-year-old added.

Armed with ropes, gloves and their knowledge, the team set off up the steep slope in the hopes of finding an alternative route to reach the boys inside the Tham Laung cave.

News of the 600ft move into the mountain comes as authorities warned rescuers were in a 'race against water' to evacuate the boys before expected heavy rainfall 

The 12 youngsters and their coach had to abandon the 'Pattaya Beach' area of the caves in Chiang Rai on Monday night and are now perched on a bumpy ledge known as 'Women's Boobs' where they were found, officials have revealed 

Rescue teams hope that water can be sufficiently drained, allowing the trapped children to wade to safety while wearing lifejackets.

A former US Navy SEAL with thousands of hours of experience of diving in difficult conditions has warned that there will be fatalities if the children have to dive out. 

Cade Courtley said the situation was currently stable and non life threatening, but that 'some of these kids are going to die' if they are made to swim through the narrow dark tunnels.  

It comes after Tham Luang operation commander Narongsak Osotthanakorn said unregistered volunteers had been diverting water back into the ground in the belief they were helping. 

'They may have some belief that their technique is effective for ground water drainage, but anything that is not in the plan must be discussed with us first,' he said. 

Mr Narongsak, the former Chiang Rai governor, added: 'We are concerned about rain. We are racing against water. Water is flowing into the cave although we have plugged its channels.'

In a further twist, he revealed that a new phone was being transported to the cave after a previous device fell in the water and stopped working.  

He also revealed the children have undergone their first day of scuba diving training in preparation for their evacuation.

They will undergo a thorough medical examination to decide whether they are fit enough for the arduous escape.  

Family members pass time near the Tham Luang cave complex, where members of an under-16 soccer team and their coach have been found alive

Chiang Rai provincial governor Narongsak Osatanakorn, who is overseeing the rescue, said 30 teams are searching for an airhole

Authorities did not under-estimate the challenge facing the youngsters, Governor Narongsak said, revealing that it took the Thai Navy Seals six hours to reach the boys and five hours to return, negotiating their way through the complex cave system.

But he said: 'The water level remains the main concern and the need for urgency.' 

It comes as it emerged there may be a secret passage out of the cave. The boys aged 11 to 16 told rescuers they have heard dogs barking, roosters crowing and children playing despite being 800 metres underground.

This has led officials to think there may be another way out through a 'chimney hole' to the surface.

Osatanakorn, who is overseeing the rescue, said 30 teams are searching for an airhole. He believes there must be one for the boys to have been able to breathe for so long.

If rescuers can drill down to the boys, that would offer an alternative to teaching them how to swim and scuba dive so they can be led to safety through the flooded cave. 

The boys aged 11 to 16 told rescuers they have heard dogs barking, roosters crowing and children playing despite being 800 metres underground. Pictured: Police at the scene

Team work: Thai soldiers are pictured carrying equipment as they make preparations for what will be a tense rescue operation

The youngsters aged 11 to 16 and their 25-year-old coach were on Monday found alive by British volunteer divers John Volanthen and Rick Stanton after nine days lost in the Thamg Luang cave network in the country's north, which they reportedly entered as part of an initiation ritual. Pictured: Rescue workers in the cave complex on Wednesday

Australian Federal Police and Defense Force personnel talk each other near a cave where 12 boys and their soccer coach are trapped

On Wednesday Mr Osatanakorn said that 'all 13 may not come out at the same time.'

He said authorities will evaluate their readiness each day and if there is any risk will not proceed.  

'If the condition is right and if that person is ready, 100 per cent, he can come out,' he added. 

It comes after a new video was released showing the boys in good spirits after 11 days underground.

The boys and their coach are seen sitting with Thai Navy Seals in the dark cave with their visibly skinny faces illuminated by the beam of a flashlight.

The youngsters, many wrapped in foil warming blankets, take turns introducing themselves, folding their hands together in a traditional greeting and saying their names and that they are healthy.

The minute-long video was recorded some time on Tuesday and was posted on the Navy Seal Facebook page on Wednesday morning.

The boys and their coach disappeared after they went exploring in the Tham Luang Nang Non cave in northern Chiang Rai province after a football game on June 23.

Rescue workers are seen by the Tham Luang Nang Non cave in northern Chiang Rai province

Meanwhile, the anguished mothers of the stranded school boys today offered prayers for the swift rescue of their beloved sons.

Nine relatives of the missing footballers lit incense sticks made offering of rice to a shrine just yards from the entrance of the Tham Luang cavern, near Mae Sai, in the far north of the country.

In a moving ceremony the mothers bowed their heads in prayer in front of statue of Buddha and called upon the deity to make the water flooding the cave recede and for their sons to be brought to the surface quickly and safely.

Among the family members was Ratdao Chantapoon, the mother of Prajak Sutham, 14, one of 12 boys from the Wild Boar football team who ventured into the underground network with their coach last month.

A friend revealed that the mothers decided to pray and make offerings to the Buddha and the sacred spirit.

A desperate search for them drew assistance from experts around the globe

Workers bring supplies for the trapped boys, who were trapped inside when heavy rains flooded the cave

While efforts to pump out floodwaters are continuing, some Thai officials have indicated that heavy rains forecast for this weekend could force them to decide the boys should swim and dive out using the same complicated route of narrow passageways through which their rescuers entered

A Thai army medic slips as his comrades carry a stretcher during a training exercise as rescuers work at the scene in Thailand

'They want to do everything they can to help their boys and get them home as soon as possible,' she told MailOnline.

'They have faith in the rescue operation to bring them out of the cave safely. But they wanted to offer their prayers to the sacred spirit to help.' 

The teammates, who were trapped inside when heavy rains flooded the cave, were found by rescue divers late on Monday night.

A desperate search drew experts from around the globe, including British divers Rick Stanton and John Volanthen, who were the first rescuers to reach the group.

Authorities said the boys were being looked after by seven members of the Thai Navy Seals, including medics, who were staying with them inside the cave.

They were mostly in stable condition and have received high-protein drinks. 

Rescuer workers prepare small diving masks to deliver to the youngsters inside Tham Luang Nang Non cave

A Thai navy officer carries a pig's head to worship celestrial guardians and spirits as the rescue operations for the child soccer team and their coach continue

Family members of the 12 boys and their soccer coach watch a video clip of 12 boys on television after they were found alive, in Mae Sai, Chiang Rai province

Huge pipes have been placed in the tunnel network in the hope of lowering the level of water in the cave network

Authorities said the boys, who had also been shown Tuesday in a video shot by the British diver who discovered them, were being looked after by seven members of the Thai navy SEALs, including medics, who were staying with them inside the cave. They were mostly in stable condition and have received high-protein drinks

Concerned family members are escorted by police close to the Tham Luang cave complex in northern Thailand