Doug Butzier, Libertarian candidate for senate, was killed in a plane crash Monday.

Butzier’s wife confirmed with KCRG-TV Tuesday morning that he was killed in the crash Monday night around 11 p.m. near the Dubuque Regional Airport.  

Lynn Lunsford, Federal Aviation Administration spokesman, said the Piper PA-46 crashed about a mile north of the runway. Lunsford said Butzier was the only occupant on the plane when he took off from Ankeny Regional Airport about an hour before he crashed.  

The National Transportation Safety Board will investigate the crash.