Roald Engelbregt Gravning Amundsen (July 16, 1872 - June 18, 1928) was a Norwegian explorer of polar regions. He led the Antarctic expedition (1910-12) to discover the South Pole in December 1911 and he was the first expedition leader to reach the North Pole in 1926. He is also known as the first to traverse the Northwest Passage (1903-06). Amundsen disappeared in 1928 while on a rescue mission. It is believed that the plane crashed in fog in the Barents Sea, and that Amundsen was killed in the crash, or died shortly afterwards. His body was never found. Amundsen was a key expedition leader during the Heroic Age of Antarctic Exploration.