(Toledo, OR)  --  Investigators are trying to determine what caused the crash of a small plane that left two people dead and one injured in Lincoln County.  Authorities say the plane went down around 4:20 Saturday afternoon in the parking lot of the Georgia-Pacific paper mill in Toledo.  The pilot, 51-year-old Douglas Nebert, and his four-year-old granddaughter, Zoey Wahl, died at the scene.  Nebert's stepdaughter, April Gleason of Seattle, was airlifted to a hospital.