On the day's main climb, Mont Ventoux, Simpson broke away early, but was soon passed by the eventual stage winner, Julio Jiménez, and four others. About two kilometres from the summit, Simpson began to zig-zag across the road, eventually falling against an embankment. While his team car helpers wanted him to retire from the race, Simpson insisted on carrying on. He went another 500m or so before again beginning to fall; he toppled unconscious into the arms of his helpers. Despite mouth-to-mouth resuscitation and the administration of oxygen, plus a helicopter airlift to a nearby hospital, Simpson died. Two tubes of amphetamines and more empty tubes were found in the rear pocket of his racing jersey. He died of heart failure caused by dehydration and heat exhaustion, with drugs a contributing factor.