On April 14, 2003, at 1140 eastern daylight time, an Aero Commander 500S, N19WL, registered to and operated by the South Carolina Department of Natural Resources, collided with the ground following a total loss of power in both engines at East Cooper Airport, Mount Pleasant, South Carolina. The public use flight was operated under the provisions of Title 14 Part 91 and visual flight rules. Visual meteorological conditions prevailed at the time of the accident. The airplane was destroyed, and the airline transport pilot and passenger received serious injuries. The flight departed East Cooper Airport, Mount Pleasant, South Carolina, at 1130, on April 14, 2003. According to the pilot, he requested the refueler to top off his fuel tanks with "100 low lead fuel". The refueler informed the pilot of the amount of gallons of fuel he placed on the airplane and had the pilot sign the fuel ticket. The pilot performed a preflight including taking fuel samples from under the wings, draining the rear fuel drain, and checking the fuel cap for security. The engine start, run-up, and taxi were uneventful. The airplane departed runway 17 on the initial take-off climb. At approximately 200 feet AGL the airplane began to lose power. The pilot ensured that the throttle, propeller, and mixture controls were in the full forward position. The pilot then rechecked that the landing gear was up and that the flap handle was in the up position. The airplane lost full power in both engines, and the pilot executed an emergency off field landing. Examination of the wreckage revealed that the left wing had broken off and the aft cabin area was crushed. According to a lineman employee at Aero-East, he spoke to the refueler shortly after the accident. The refueler explained to the lineman at the time of the accident he was refueling a helicopter as he watched the airplane takeoff. He indicated that the airplane did not seem to be making full power as it leveled off, bank to the left and collided with trees. The lineman asked the refueler if he had refueled the airplane, and he said that he had refueled the airplane with 58 gallons of fuel. The manager of Aero-East ordered all fueling operations stopped, fueling records secure, and fuel samples taken from the 100LL AVGAS truck. The lineman checked the fueling receipts and found a discrepancy on the fuel receipt for the accident airplane. The word "AVGAS" had been handwritten over the product description. The lineman checked the other fueling records and found that the fuel truck logs were also altered. In an interview with the refueler, he stated that he mistakenly used the Jet-A fuel truck instead of the AVGAS 100 low lead truck, and he had pumped 58 gallons of Jet-A into the airplane. The refueler affirmed that the paper work errors were to keep the product inventory in balance because he thought he made wrong entries on the other forms. The document entry changes were made prior to the accident. Fuel samples from the AVGS truck, JET-A truck, left engine and right engine were sent to General Engineering Laboratories, LLC for a fingerprint analysis. Both samples of fuel taken from the left and right engine contained approximately thirty percent AVGAS 100 low lead and seventy percent Jet-A fuel.