Verëvkin died in 1983 while exploring a siphon in the cave Su-Akan,[8] located in the Sary-Tala massif, now Kabardino-Balkaria, Russia.

During an expedition in 2021, PST found the body of a caver, who died exploring on his own, at −1,100 meters (−3,600 ft).

He was later identified as Sergei Kozeev, who left his home in Sochi (Russia) on 1 November 2020 and began descent into Veryovkina, where he spent around a week at a −600 meters (−2,000 ft) permanent camp.

Then he continued his descent down to technically challenging parts at −1,100 meters (−3,600 ft) where he got stuck, and died of hypothermia.

He did not bring stirrups necessary to climb out of the lower, perpetually wet, regions of the cave.