The airplane impacted terrain at about 0608 Central time following a takeoff into instrument meteorological conditions. The non-instrument-rated commercial pilot was fatally injured. The flight departed without a flight plan but under an SVFR clearance. One witness observed the airplane taxi, take off and climb to about 100 feet agl. He stated the airplane appeared to be flying normally. The witness stated weather at the time was being reported by the AWOS as 300 feet overcast and five miles visibility. Another witness described fog at the airport at the time of departure. A witness who was about one mile from the impact site described heavy fog in the area when he left for work at 0550. Examination of the airplane wreckage and accident site indicated the airplane impacted trees and terrain in about a 35-degree left bank with a 30 degrees nose-low attitude. The wreckage was contained in about a 150-foot diameter circle. All control surfaces were located in the wreckage and flight control continuity was verified from the cockpit to each aileron, elevator and rudder control surfaces.