They arrived on the mountain earlier than the 5pm generally suggested (for example, this site states "Camp was set up around 5 pm on a slope of Kholat Syakhl just 16 km (10 miles) from Mount Otorten"), because the 2 photo's said to show them digging the trench in a blizzard are taken in daylight, and it was sundown at 4:29pm. An important detail as this extends the hours without stove heating on an exposed mountain ridge.
They dig their trench, and begin setting up the tent. Ascending the mountain pass and digging that trench, deeper on one side than normal to compensate for the slope, would have worked up quite a sweat, and when you do that in sub zero conditions you risk a chill if you cannot get dry.
The better-dressed Semyon and Tibo are outside, not to urinate, but tasked with completing the ridge ropes, after which Igor, inside with others removing damp outer clothing, can suspend the stove and the pipe flue they have carried wood up a mountain for (wood was found in one corner of the tent).
I believe a military helicopter was then heard approaching the pass. The hikers may have learned of the escapees from the residents of Vizhay and deduced what this was likely about. The military may have been in that specific area following a set of Chinese Whispers producing reports of a group of strangers passing through (the hikers). Alternatively, there may have been a military exercise underway.
The numerous witness sightings of orange orbs in the sky could be the search light of a helicopter, or several, where atmospheric effects alter the perception of colour at distance while the rotor sound is not heard due to distance and wind direction.
The Yak-24 troop carrier, a twin rotor, capable of carrying up to 30 troops and a vehicle slung underneath, similar to a Chinook (note the angle and shape of the lamp).One of Semyon's final photo's (enhanced & colourised)Their immediate reaction is to hide. They are highly conspicuous in an 8ft long dark coloured tent on a white mountain ridge and must work with what material they have around them, snow. I'm sure that out of preference they would sooner have nothing to do with the military in 1959. This could be due to any number of specific reasons, or a collection of them. For example, two of them had illegal Fischer knives, only Aleksander Kolevatov had a permit for his, Tibo & Yuri K did not. Tibo's full name is French, and his father was executed under Stalin, so he may feel he would be under automatic suspicion by a military commander radioing in their IDs, all of which remained in their rucksacks.
In the short time available, and while the helicopter/s search the forest and valleys, and not having completed the tent set-up, they imperfectly drop their tent, give up all notion of using the stove, which would put out smoke, and cover the tent with the snow spoil they have dug. The intention is to make the tent look abandoned when seen from the air, as if subjected to a small avalanche, or collapsed under the weight of snowfall.
Wind scour blows away freshly fallen granular snow on the pass, preserving raised footprints when a hiker's weight has compacted the snow they trod on, and that same wind scour should also clear any on the tent. But this clumpy snow remains on the tent until the rescue party arrive as it's already compacted, and been trodden on. This would also explain how Igor's torch came to be found atop of 10cms of snow on the tent with only a small amount of snow above. And of course snow will not settle on a tent and make it collapse when one side has been cut open.
The effect of wind scour above the tent siteThe complex array of ridge ropes employed at a previous site, when on a level, involving 3 loops through the centre eyelets and a fourth rope to tension the skis, which in turn are double anchored to ski poles.The tent as found, one ski is in entirely the wrong position, and there is little evidence of ridge ropes which should fall slack and be shown tied to skis, and evidence of them running across the tent even if part hidden by snow. Look at the 'snowfall' on the tent and compare it the trench spoil around it.Helicopter search lights, as used in the rescue missionThey would lay down in the trench under the canvas and snow, many of them partly undressed, in what amounted to a cold coffin, for however long they felt they must, and motionless, and with the greater part of their body in contact with the ground, the least dressed developed hypothermia. During this confinement Semyon would take some of his photo's through the canvas. They'd peep out of holes cut for breathing, and eventually expand on these to cut/tear their way out from laying horizontally, and when suffering the confusing effects of hypothermia, explaining all the inefficient, time-consuming 'emergency evacuation' cuts when made by 9 people laid down inside.
Igor would be shivering and mumbling, incoherent with hypothermia, so the better dressed Semyon would take charge. He will have seen hypothermia kill his comrades in action, and recognise the symptoms, and he'd determine they must head down the pass and start a fire in the woods. They will extinguish it with snow if the helicopter returns.
Igor, the group leader, is so out of it with the effects of hypothermia he leaves without his shoes, drops his coat, does not take a hat or gloves, and forgets his torch. They do not retrieve what they need due to hypothermia affecting their cognition, they forget to take an axe, and this is made yet more difficult through the tent's collapse and snow covering. Semyon cannot risk the time required to dress them all, they have to get down off that mountain ridge.
They assemble nearby and walk in single file down the pass, led by him. The tallest/heaviest, Yuri D, is at the back, indicated by the footprints, and poorly dressed he will take the brunt of windchill and become the first to die. No attempt is made to find the tent again, there are no footprints showing them making any attempt. Experienced hikers will know when they have travelled downhill in an emergency and make some attempt to retrace their steps, tracking their own movements in the snow, so they have not 'lost sight' of the tent; they have purposefully left it behind. Evacuated.
The 1 mile journey down the pass sees them begin to collect injuries from falls and rolls. Hypothermic people cannot reliably walk 20 to 30ft in a straight line, it's like they are drunk. Appropriately, one hiker's tracks were said to deviate and then rejoin the group.
Walking in line in the dark means someone following behind falls on top of someone who has fallen in front, and the person underneath may begin to develop hairline rib fractures from this crushing pressure on the many rocks which jut out of the snow, and those which reside just beneath the surface. Had Lyuda walked 2nd after Semyon this begins to explain the development of the rib fractures they both sustained.
The snow works to soften & spread the impact to reduce surface injury but the pressure still travels through the body until it meets unyielding bone. They avoid the common collar bone (clavicle) fractures through the energy of a forward fall turning into a roll downhill, but that it turn delivers blows to the temples. And they develop injuries to the back of their heads from falling onto their backs, unprotected by the usual rucksacks (or these are sustained during later resuscitation attempts or the agonal stages of hypothermia).
Colourised rescue photo's showing the minefield of rocky outcropsThe modern day hikers who walked down without problem staged an unrealistic test. They needed most of their number to be suffering from hypothermia when they set off, to not be wearing shoes, gloves, hats or coats, and have only cotton clothing on. I'd put money on them not arriving at the cedars unscathed if they did.
Semyon heads for the tallest tree, the cedar, its evergreen foliage providing shelter from the elements, and also somewhere to hide from the helicopter should it return. They cut hardwoods with a knife, because hypothermia has caused them to forget to bring their axes. Tibo possibly falls from the tree sustaining a head injury. They will later drag him to the den because he continues to show signs of life, though unconscious. Igor does most of the tree climbing and generates sores around his ankles, unique to him.
Yuri D & Yuri K go into Stage 3 hypothermia, and lay prone, rigid. They had been positioned close to the fire while the others looked for fuel, and in their agonal stages (used at autopsy to explain scratches) they thrash around until Yuri K's leg and Yuri D's scalp get too near the embers. Due to being unconscious they wouldn't feel anything/react and this communicates to the others they must be dead. They cut off their clothing as sleeves and socks, and Igor takes Yuri D's shirt because he has no coat.
Zina has likely pressed on ex-boyfriend, Yuri D's, chest to try to revive him, explaining the mention of chest pressure and fluid around the mouth at autopsy. Yuri K will have bitten into his own hand to try to stay awake, but owing to the numbing effects of hypothermia, which reduces blood supply to the extremities (hence frostbite) he did not feel this so bit harder still, until he bit off a piece of his own skin. He then passed out.
Plan B, they cannot sustain the fire and the deaths have brought home how critical their situation now is. They cannot simply hole up in the forest overnight and return to the tent the next day. They head to the ravine and dig a foxhole den by hand, cutting evergreen firs as lining, but this exhausting toil sees 3 more succumb to Stage 3. They try to restart Semyon and Lyuda's hearts with chest pressure but end up cracking their ribs, which may already have hairline fractures from falls downhill.
This era was (just) pre-CPR, which was introduced in 1960, although the university student hikers may have known of it. One report on cardiac arrest victims at autopsy revealed up to 92% had sustained chest fractures during CPR resus, the areas involved being around the sternum and at the sides where the pressure travels. Even in western reports dated 1964 some cadavers had up to 8 rib fractures. Prior to CPR (mouth-to-mouth combined with vigorously pumping the chest focussing on lungs and heart function) it was chest pressure and lifting an arm (the heart and circulation).
http://www.forensicmed.co.uk/pathology/cpr-related-rib-fractures-in-adults/#:~:text=Prospective%20post-mortem%20studies%20following%20CPR%20in%20adults%20show,thirds%20of%20those%20with%20fractures%20have%20multiple%20fractures.
They realise the futility of trying to revive any of them, the scale of the situation before them is overwhelming, and as the numbers dwindle they have to start thinking of their own survival. The 4 all appear dead due to hypothermia stage 3, and so they slide their bodies into the ravine, all heads to one side, and cover them with snow from the bank to hide them from the air. They don't want corpses in the den. Semyon and Lyuda are already dead from resus attempts, and the freezing water saturating their clothing finishes off the unconscious Tibo, and Aleksander Kolevatov, with Stage 4 hypothermia.
Some of the faces are later part-exposed by snow melt, and carrion birds peck out the eyes (as likely explains the same happening with some of the Chivuray hikers who went missing on the Kola peninsula in 1973). Heavy snowfall later covers them, and the den. Lyuda dies with her mouth open, and either her tongue is taken by birds or the flowing water directly into her mouth denudes the oral cavity, the water washing away the decomposing tissues.
At some point later the remaining 3 leave the den, recover it, and head back to the tent. This could be at daybreak. The autopsies suggest they all died within 6 to 8 hours of eating, because food was found in the small intestine, and that is the normal digestive time, but the metabolism will be slower when cold, something true of all mammals.
They need food for energy and to stay warm, their blood sugar is dangerously low, and they do not have much body fat to survive on. Additionally athletic males survive less well than females with hypothermia because physiologically they have less subcutaneous fat. The weather may have stabilised, and it will take them 2 hours to reach the tent, 2 hours or more to rest, eat, and assemble what they need, and an hour or more to drag things back down the pass, and they have only 8 hours of daylight available, so there is a narrow window of opportunity, operating around the changing weather, allowing for only a few hours rest in the den during which time their core temperatures may slightly improve.
They set out, walking, and then crawling on all fours, at times using their palms and fists to avoid frostbite to their fingers from repeatedly plunging them into snow (explaining the knuckle injuries unique to these 3 on both hands), and on their knees (Igor doing this more, because he had no shoes, and kneecap injuries were unique to him). Igor leads but dies first, the other two continue, Rustem's head injury, possibly generating a blood clot and while under exertion sees him suddenly collapse, explaining his ice bed, and Zina gets furthest, half way to the tent, as she may have expended the least energy, has that little bit more fat, and is the better dressed. A blizzard may have arrived to halt her progress.
A military helicopter returns in daylight and sees the bodies on the pass, lands, or has men abseil down a rope to turn the bodies, explaining the movement after death. Any tracks are later covered by snow, as are the bodies. They have no idea about the others. Later the commander files a report about dead hikers, explaining how, according to one documentary which uncovered some military papers, it seems they knew about 'missing hikers' before the families contacted the university to raise the alarm.
In conclusion the military did not directly kill the hikers, but the paranoid fear of the State machine indirectly did, because it prevented them starting their overnight life support machine, their stove, while they were caught up in a military search zone, or some kind of exercise. This delay set in motion an overnight battle with hypothermia. The Cold War killed them...in their battle against the cold.