Brit cave diver’s mum reveals fears for hero son spearheading deadly rescue after elite navy SEAL dies in flooded cavern

THE mum of a hero Brit spearheading the rescue of 12 boys in Thailand today revealed her fears for her son after a Navy SEAL died inside the flooded cave.

Cave diving expert John Volanthen, 47, and fellow Brit Rick Stanton, were the ones who found the boys alive inside the tunnel earlier this week.

Despite being world-renowned experts at underwater cave rescues, their work remains fraught with danger - a fact hammered home by the death of an elite diver at the site.

Saman Kunan, 38, died from a lack of oxygen as he attempted to swim back through the underground labyrinth to safety last night.

John's mum Jill, from Brighton today told The Sun Online her "tummy turned over" when she heard the news about his death.

She added: "I'm actually very concerned, and even when (John) does extreme runs, at 130, 150miles, I worry. They're all natural things that a mother does worry about, but you just accept it as part of life.

What we know so far:

• The football team made up of 12 boys aged between 11 and 16 and their coach ran into trouble on 23 June
• They were visiting the cave network in Chiang Rai when monsoon rains trapped them deep inside
• They were found safe on Monday night by British divers, who discovered them huddled together on a ledge about 1.2miles inside the network
• They are all in reasonable health - one diver said they were "very weak, but alive"
• The military is sending in provisions to last them up to four months while they assess rescue options
• The children are being taught how to dive and have been given masks to practice breathing 
• A Thai navy seal has died during the rescue mission from a lack of oxygen
• A devastating monsoon which could flood the cave and leave them stranded for four months is closing in

"I feel very sorry for the gentleman, I feel sorry for his family, and all the people involved. Someone has lost their life and that's very important and I'm extremely sorry for his family."

Jill, 80, has previously spoken of her pride for her son, who has performed scores of dangerous underwater cave rescues over the past two decades.

He and Rick remain in Chiang Rai, Thailand, where they are working with international team of rescuers to try and rescue the 12 boys and their football coach.

Aged between 11 and 16, the brave lads and their coach, 26, have been inside the flooded Tham Luang network since June 23, after becoming trapped after entering it to carry out a local initiation ritual.

Heroic Saman lost consciousness on his way out of the Tham Luang cave and could not be revived by his colleagues.

He had left the Navy last year, but returned just to help the rescue effort.

"The conditions in the cave are tough," Admiral Apakorn Yuukongkaew, commander of the SEALS unit, told reporters on Friday.

"Once he placed the oxygen tanks he became unconscious on his way back. His buddy tried to administer first aid, when there was no response he tried to move him," Apakorn said.

"We won't let his life be in vain. We will carry on".

Following Saman’s death, authorities have admitted for the first time that the stricken kids cannot wait in the cave until the rainy season passes in October.

Officials said the window of opportunity to free the group is limited.

The cave system in northern Thailand is losing oxygen as rescuers continue to try and deliver air supplies to the kids.

A ventilation pipe, which is also being coached through, must reach the children today.