TRENTON, S.C. (AP) -- Authorities say a Graniteville man has died after the plane he was piloting crashed near a small airport in Trenton. The Edgefield County coroner's office says 56-year-old Richard Showalter died Monday night when his twin-engine plane went down near the Twin Lakes Airport, which straddles the line between Aiken and Edgefield counties. Authorities say Showalter was the only person on the plane. An autopsy was scheduled Tuesday. Federal authorities are investigating what caused the crash.