The National Transportation Safety Board is investigating Tuesday night’s fatal plane crash in Sauk County. The NTSB identifies the aircraft in which five adults and one child died as a single engine six seat Piper PA-46. Preliminary information has the plane at 24,000 feet when the pilot reported icing, requesting and receiving approval to descend from air traffic control. The aircraft entered a right descending turn that increased in rate until communications and data tracking were lost. Investigators will document the scene and examine the aircraft which will be recovered to a secure facility for further evaluation. NTSB investigations involve three primary areas: the pilot, the aircraft and the operating environment. Witnesses or those with surveillance video or other information that could be relevant are asked to contact the agency at [email protected].