At last that I could write that promised.
In the first, allow you to correct: that case with a fireball about which I spoke was not in Chivruai (it is Kola peninsula), and on Сaucasus. Distance and a difference between them same as between Alaska and California. It is truth there necessary exchange mountains there.
This case is how it is described by the head of group of those climbers Vladimir Kavunenko it is possible to read (in Russian) under this reference http://kmvline.ru/lib/kavunenko/18.php
I will tell this story my words. Vladimir Kavunenko it was said before me at 1979 at meeting of federation of climbers and the hikers of sports club "Burevestnik" which united students, graduate and professors of universities of the USSR, and as scientific and academic. I there was as the vice-president of branch of the hikers as the volunteer (did not get money for this work).
There was a president branch of climbers Evgenie Tamm ( https://ru.wikipedia.org/wiki/%D0%A2%D0%B0%D0%BC%D0%BC,_%D0%95%D0%B2%D0%B3%D0%B5%D0%BD%D0%B8%D0%B9_%D0%98%D0%B3%D0%BE%D1%80%D0%B5%D0%B2%D0%B8%D1%87
unfortunately there is no reference in English) whom friend Kavunenko was and he has invited Kavunenko to tell about this case. Evgenie Tamm headed expedition to the Everest in 1982 when our climbers have ascent on top the Everest on the SW face (it there is the most difficult route on this mountain till now) in number of 11 persons https://ru.wikipedia.org/wiki/%D0%9F%D0%B5%D1%80%D0%B2%D0%B0%D1%8F_%D1%81%D0%BE%D0%B2%D0%B5%D1%82%D1%81%D0%BA%D0%B0%D1%8F_%D0%B3%D0%B8%D0%BC%D0%B0%D0%BB%D0%B0%D0%B9%D1%81%D0%BA%D0%B0%D1%8F_%D1%8D%D0%BA%D1%81%D0%BF%D0%B5%D0%B4%D0%B8%D1%86%D0%B8%D1%8F
To my regret I cannot find this reference in English so quickly.
Now I will tell about how there was this event with a fireball.
In result (it is article Vladimir Kavunenko + my memoirs and translation) I can tell so:
On August, 17th 1978 five climbers went down from top of mountain “Trapitsia (Trapeze)” (it is the western Caucasus http://www.nhpfund.org/nominations/western_caucasus.html
mountain the “Trapeze” http://www.mountain.ru/article/article_display1.php?article_id=2616
) and have stopped on a lodging for the night at height of 3900 metres (12800 ft).
Kavunenko has told about it approximately so itself (it from other article about this case):
«I have woken up from strange sensation. Someone has got into tent the stranger. I have put out a head from a sleeping bag and have stood with surprise. On distance of 1 metre from a tent floor the bright yellow sphere in the size as a tennis ball hung." That this such and whence it undertook? "- I have thought and wanted to declare alarm. But I have not had time to shout I all it as the sphere has plunged into Korovin's sleeping bag. Wild shout was distributed, and fiery ("newcomer") has jumped out therefrom and has started to float smoothly over other sleeping bags. It disappeared that in one, in other sleeping bag by turns. Each time was distributed heart-breaking shout of the sleeping person.
I was as is constrained by not clear force, and lay without movement, as though be paralysed. All people lay in the sleeping bags. When the sphere has got into my bag, I have felt a severe pain, me me burnt down with the welding device, and I have fainted.
After a while I have come to the senses, and have seen the same yellow sphere which periodically, observing only to it known law, got into sleeping bags. Each time such "visiting" caused desperate shout of the person. So has repeated some times. Position was awful. When I have come to the senses again, it seemed in the fifth or sixth time) a pain, the sphere of a devil in tent any more was not.
When I being in a bag, I could not stir any hand, any foot. The body burnt, and it has turned to the centre of a monstrous pain completely. I have again fainted...
In hospital where us delivered by helicopter, at me have counted seven wounds. It were not burns: it were pieces of muscles which have appeared pulled out and burnt down to bones. In the same condition there were also my friends - Shitinin, Bashkirov, Carpov.
the fiery sphere has killed the fifth climber (Oleg Korovin). Probably, its sleeping bag lay on a rubber mattress and has been well isolated from the earth.Their tent has been laced up from within. In it were: radio transmitter, ice axe, the curtailed cable and other metal things. But the fireball has not touched any subject. People have suffered only. Strange there was all it (as though there was this visitor). It seemed that it it is conscious, spitefully, as the sadist, scoffed at us, betraying their terrible torture
.»What weather then was:
«It was cloudy, but there were no signs of approach of a thunder-storm. Those who have survived, not once saw, how there are fireballs in mountain areas earlier. But they considered that it was torture or it was that that another similar.
That it could be, they did not know. Fireballs they observed not once. They (fireballs) appeared either before a thunder-storm, or after it more often and they quickly disappeared. As a rule. This fiery sphere was in tent and (as they thought) scoffed at them. They thought that it was something another... Anybody from them has not noticed, when and as this "newcomer" has left.
The special commission organised under the analysis of this event in mountains of Caucasus, recognised in this "newcomer" as a fireball.
It is that I remember also to me it was possible to read in other articles in addition. Therefrom I took many citations and have tried to translate into English.
It is a unique case which is described authentically and in detail when the fireball caused events with travellers.
You can easily compare result of this event and event of Dyatlov group.
Further I would like to comment on some questions which set in this section of a forum about Dyatlov group.