OKLAHOMA CITY (AP) – A National Transportation Safety Board report on an Oklahoma plane crash that killed two Kansas men says a part of the aircraft was found more than a mile from the crash site.

The April 7, 2013, crash killed retired gynecologist Ronald Marshall of Manhattan, Kansas, and Chris Gruber, the development director for the college of veterinary medicine at Kansas State University in Manhattan.

The NTSB factual report released Wednesday says the fiberglass belly skin panel of the plane was found about 1.4 miles from the site. It does not offer a suspected cause of the crash.

The report says the single-engine Mooney M20J piloted by Marshall took off from Tulsa International Airport at 5:47 p.m. and crashed about 13 minutes later in the back yard of a vacant home near Collinsville.