In 1897, Salomon Andree, the first Swedish aeronaut, set out on an expedition which involved flying a hydrogen-filled balloon from Svalbard to Russia or Canada, passing over the North Pole along the way. However, the balloon proved uncontrollable. It quickly lost its hydrogen and crashed into the ice just 65 hours after take-off.
33 years later, the expedition’s final camp was discovered by accident, along with Andree’s diaries. It turned out, that he and his fellow explorers had walked across many miles of drifting ice, without equipment or suitable clothing. They also managed to survive for weeks after the crash by hunting polar bears.