GREENSBURG, Ind. (AP) _ A semi tractor-trailer truck went airborne briefly after veering off an interstate, up a hill and crossing a state highway in southeastern Indiana before bursting into flames. 
 
  State police say the truck driver 30-year-old Ryan Young of Owenton, Ky., suffered some minor facial and head injuries and his 7-year-old son sustained some minor scratches in the accident. 
 
  Young told state police he was headed east on Interstate 74 near Greensburg about 1:39 p.m. Thursday when he swerved to avoid a vehicle drifting into his lane. He says that caused him to go off the road and up the hill, causing the fiery crash.
 
  State Police Sgt. Noel Houze says the truck's fuel ignited after its tanks were torn when it struck a guardrail. He says the investigation is continuing.