MONTEVIDEO (AP) - Family members say the two adult brothers killed in a plane crash in western Minnesota were not only siblings - they were best friends.

Mark Schultz of Sleepy Eye and Steven Schultz of Brooklyn Center died Sunday when their small plane went down in a field near Montevideo.

Relatives say the brothers hunted, fished and flew airplanes together.

Mark Schultz was a vice president at First Security Bank in Sleepy Eye. Fifty-one-year-old Steven Schultz was employed by Medtronic and had recently invented a device for Parkinson's disease patients.

The Federal Aviation Administration is investigating.