Investigators in north Florida are trying to solve the mystery of a young Kentucky couple found dead at an Interstate 95 rest area.

The St. Johns County Sheriff's Office says 23-year-old Kenneth L. Oldham of Morehead, Ky., and 22-year-old Kayla R. Hinton of Olive Hill, Ky., were found dead Wednesday inside their car.

Sheriff's spokesman Sgt. Chuck Mulligan says family members did not know why the couple was in Florida. The bodies appeared to have been there for several days, but authorities say they do not suspect foul play.

The cause of their deaths has not been released, and detectives are looking at the possibility the two may have been overcome by carbon monoxide fumes while parked at the northbound rest area on I-95 near St. Augustine.