The aircraft, operated as a Part 135 cargo flight, collided with the ground in a nose-down, near-vertical attitude at 1210 Central time. Visual conditions prevailed; the Airline Transport-rated pilot received fatal injuries and the airplane was destroyed. While in cruise flight at 16,000 feet, the pilot requested and was cleared to make a 360-degree turn to the left. Shortly afterward, the pilot requested a 360-degree turn to the right. The pilot then requested radar vectors to the closest airport and reported an asymmetric fuel condition. Controllers cleared the flight to 4000 feet. About a minute later the pilot transmitted Mayday six times and shortly after this radar and radio contact with the flight was lost. Witnesses saw the aircraft descending at a high rate of speed in a near-vertical attitude. It then collided with the ground and exploded.