Weather at Sioux City was poor: 800 feet overcast, 3 miles visibility in fog and light freezing drizzle. Flight 982 took off from runway 35 and, upon gear retraction, rolled violently 90ø to the right. The roll was counteracted, but the left wing struck the runway. The DC-9 crashed and came to rest in a grove of trees, 1181 feet past the runway end. PROBABLE CAUSE: “A stall near the upper limits of ground effect, with subsequent loss of control as a result of aerodynamic and weight penalties of airfoil icing. The flight crew failed to have the airfoil ice removed prior to the attempted take-off from Sioux City. The Board also finds that the crew selected an improper takeoff thrust for the existing gross weight condition of the aircraft.”