A 35-year-old man was killed Thursday afternoon when his car hit a tractor-trailer head-on on Hwy. 74 in neighboring Monroe County.The full release from Allison Selman-Willis, PIO for the Monroe County S.O. follows:A Macon man was killed yesterday, Sept. 15, 2011, on Hwy. 74 near milepost 12 in Monroe County around 4:45 p.m. According to Kaitlyn Smith, 20, her husband Charles Smith, 35, was possibly in some sort of medical distress which caused him to begin driving erratically. Mrs. Smith stated that their Hyundai Accent left the roadway several times then crossed the center line and crashed into a tractor trailer head-on. The driver of the tractor trailer, Frank McCue,49, of Macon sustained only minor injuries. Charles Smith was pronounced dead at the scene of the accident and his wife, Kaitlyn, was transported to the Medical Center of Central Georgia for treatment. The investigation into this accident continues.