Doug Butzier, the Libertarian Party nominee for U.S. Senate in Iowa, was killed in a plane crash, authorities said Tuesday. He was 59. Key West Fire Chief Brian Arnold confirmed the crash and Butzier's death in a brief interview. He said Butzier was piloting an airplane late Monday night when it crashed roughly a mile from the Dubuque airport, which Butzier was approaching. No one else was in the plane. The National Transportation Safety Board said it is investigating a crash in the Dubuque area that caused no ground injuries.