An Army reservist has described how he repeatedly attempted to revive a comrade who died just 500 metres from the end of an SAS test march.
An inquest into the deaths of three reserve soldiers, including Lance Corporal Craig Roberts, heard that he was found collapsed near a stream by another special forces candidate, codenamed 1D.
L/Cpl Roberts, originally from Penrhyn Bay in north Wales, Lance Corporal Edward Maher and Corporal James Dunsby all died from the effects of hyperthermia in July 2013.
In evidence to the fourth day of the inquest, 1D said efforts to revive L/Cpl Roberts on the Brecon Beacons lasted for around two hours.
The soldier told the hearing in Solihull, West Midlands, he was on his hands and knees ascending a rocky hillside when he heard heavy breathing.
Speaking in a strong Scottish accent from behind a screen, 1D said: "I saw a Bergen (rucksack) and someone lying down about 20 metres up.
"I got to him and realised it was Craig Roberts. He was lying on his stomach with his Bergen off. I lifted his head and was shouting 'Craig, Craig' but there was no response."
Having pressed the emergency button on L/Cpl Roberts' tracker, 1D rolled his colleague over and put him into the recovery position.
"At this point I was looking around for help and I saw Soldier 1E coming down on the other side," 1D said.
"Craig was probably convulsing about about every 10 seconds. He was quite pale, he was quite hot and his shirt was sweaty.
"I shaded him with my hat and poured water on him to cool him down."
L/Cpl Roberts then stopped breathing and 1D commenced CPR as soldier 1E arrived.
As 1E took over efforts to revive L/Cpl Roberts, the inquest heard, 1D went 20 metres further up the hillside and found the dying soldier's jungle hat and weapon.
A three-strong team of soldiers with medical equipment responding to the emergency tracker activation then arrived to help L/Cpl Roberts around 15 to 20 minutes after he was discovered, 1D told coroner Louise Hunt.
"I took them to where Craig was," 1D added. "We all helped with CPR and moved him him into the shade of a nearby tree until mountain rescue, paramedics and air ambulance arrived.
"In total we are probably trying for about two hours to get him back."
Soldier 1D, who was thanked for his efforts by L/Cpl Roberts' parents through their lawyer, was asked by the coroner if he had formed a view as to why something so awful had happened.
Claiming the day was the hottest he had ever experienced on the Brecon Beacons, 1D responded: "I just think the weather that day was a bit freakish, out of the ordinary.
"The build-up obviously wasn't in those conditions. I don't think fitness had anything to do with it. Craig seemed like a really fit guy and we all sort of knew our limits."
Soldier 1E, who joined the Army Reserve after serving in the RAF for nine years, told the hearing: "My view is that there is not one factor, there is a series of factors which all fell into place.
"One is undoubtedly the heat and the lack of wind. Another is the length of the march."
L/Cpl Roberts was living in Lee, south-east London, and worked as a teaching assistant in the capital.
The University of Leicester graduate, who had previously worked for a financial firm and served as a reserve in the Royal Anglian Regiment, was found collapsed at about 3.30pm on July 13 2013.
The inquest heard paramedics arrived at the scene at 4.46pm and an air ambulance at 5.05pm.
Soldier 1E said another factor on the day of the march had been soldiers' determination not to be medically withdrawn by directing staff at checkpoints.
"You do your best to hide the fact that you are in trouble if you are," he told the inquest. "You straighten up and tell them you are enjoying it, you're having fun."
A chief instructor involved in preparing 37 reservists in the lead-up to the march said around half of them had previous military experience, while the rest were "direct civilian entry" candidates.
The inquest heard that the reserve regiment instructor, 1F, had not read a joint services flowchart advising that activities should be stopped if a heat injury occurs.
Another march went ahead a day after the fatalities, although one reservist was not in the right frame of mind to leave the camp.
During his testimony, 1F said he could not remember whether the "tragic" events of July 13 had been mentioned in a meeting ahead of the following day's march.
Ms Hunt asked 1F: "I find it hard to understand that you didn't discuss at all in that meeting, we have two people dead, one person in intensive care, several others injured, and there was no discussion about how did that happen?
"Bearing in mind it was known that it was going to be hot the next day, is that what you are telling me?"
1F responded: "I can't recall a specific discussion."
It also emerged that equipment to conduct a wet-bulb globe test (WBGT) to assess the "heatwave" conditions on the mountains.
Although the WBGT procudure had been used in 2012, 1F said, the testing equipment was being recalibrated in July 2013.
The inquest continues tomorrow.