On February 13, 1999, about 0630 central standard time, a Beech A24R, N24624, registered to an individual, collided with a ditch and a tree during taxi to takeoff at Philadelphia Airport, Philadelphia, Mississippi, while on a Title 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft received substantial damage and the private-rated pilot received minor injuries. The flight was originating at the time of the accident. The pilot stated he had trouble getting the left wing tie down rope through the wing tie down fitting the night before the accident, due to a knot in the rope. As he added a quart of oil to the engine during the preflight inspection he remembers untying the tie down ropes. He does not remember struggling with the left tie down rope to get the knotted end back through the fitting. He completed the preflight inspection, got in and started the engine. As he applied engine power to begin taxiing, the aircraft jerked to the left and he was thrown toward the middle of the aircraft. He believes he pushed the engine throttle further forward as the aircraft jerked. The aircraft continued to move across the ground and he reduced the engine throttle to idle. He thought he had regained control of the aircraft and became distracted by the landing gear in transit light which had illuminated. The aircraft continued to move forward and went into a ditch and collided with a tree.