The deadly avalanche was triggered by a moment magnitude scale 6.4 earthquake which struck at a depth of 216.8 km beneath the Hindu Kush mountains in neighbouring Afghanistan.

Some of the largest earthquakes have exceeded magnitude 8.0, while even moderately large 6.0 events have resulted in thousands of fatalities.

At the time of the quake, 45 mountaineers were at Camp II, at an elevation of 5,300 meters on the Razdelnaya Route to summit the peak.

[6] The team consisted of 23 members of the Leningrad Mountaineering Club, six from Czechoslovakia, four Israeli, two Swiss, and a Spaniard.

According to them, some team members were still conscious after the avalanche buried them, but rescue attempts failed when the debris hardened into glacier ice.

[8] Survivors and witnesses on the mountain did not report any shaking from the earthquake, presumably because the ice acted like a shock absorber.