The National Transportation Safety Board has released its preliminary report on the Nov. 18 air ambulance crash northwest of Mandan.
According to the accident report, at about 10:40 p.m. Nov. 18, the Bismarck Air Medical plane "was destroyed when it broke up in-flight" and landed in an open field near Harmon.
The crash claimed the lives of pilot Todd Lasky, nurse Bonnie Cook and paramedic Chris Iverson.
The flight originated from Bismarck Municipal Airport at 10:30 p.m. and was en route to Sloulin Field International Airport in Williston to pick up a neonatal patient.
According to the report, the Cessna 441 plane climbed on a direct course until reaching 14,000 feet above sea level. The plane entered a steep right bank and radar contact was lost. No distress calls were received.
Wreckage for the plane was scattered for about a mile long and 600 feet wide in a snow-covered field.
Morton County Sheriff Kyle Kirchmeier said the plane was not struck by anything and there was no fire. Weather also is not believed to have been a factor.
A final report on the investigation could take a year or two, according to Elizabeth Isham Cory, a spokeswoman for the Federal Aviation Administration.