VI, last occupied by Mallory and Irvine. Eventually, the team abandoned their search for Irvine to rescue several other climbing parties stranded on the mountain and in deep distress. The victims included two Chinese glaciologists, three Russian climbers, an American guide, and his Guatemalan client. Several of the climbers were suffering from high altitude cerebral oedema, a condition where the victim can hallucinate, lose balance, and eventually become unable to walk, due to lack of oxygen (which, high up on Everest, is only one-third the partial pressure of oxygen at sea level) in the brain. This condition has led to many deaths and injuries in mountaineering. In early 2004, Jake Norton and Dave Hahn returned to Everest with a film team and support from Sherpas Danuru and Tashi to look once more for evidence of Irvine and answers to what happened to Mallory and Irvine in 1924. While the team was able to scour the Yellow Band, the combination of a small team and uncooperative weather eliminated most chances of a major discovery. During that same season, search parties were on the mountain from the website EverestNews, as well as an expedition led by Russell Brice, which included Graham Hoyland (Howard Somervell's grand-nephew and member of the 1999 Mallory and Irvine Research Expedition). In 2007, the Altitude Everest Expedition led by Conrad Anker, who had found Mallory's body, tried to retrace Mallory's last steps. Jochen Hemmleb led another search expedition in 2010, examining new terrain on the Northeast Ridge, specifically near a feature called "The Warts." Nothing of consequence was discovered. See also List of Mount Everest expeditions External links 1999 Mallory & Irvine Research Expedition website by MountainZone 1999 Mallory & Irvine Research Expedition website by PBS/NOVA 1999 Mallory & Irvine Research Expedition website by AFFIMER Mallory and Irvine Research expedition 2001 Mallory and Irvine Research expedition 2004 Mallory's body shortly after its discovery on May 1, 1999 Mallery and Irvine team member Jochen Hemmleb Interview Mallery and Irvine team member Jake Norton Interview 1999