I see jacdec have changed the wording substantially, yet they are nowhere closer to the truth.
The aircraft was performing an engine test in the test cell adjacent to hangar 4/5 in CPH. There were 3 engineers on the flight deck and one on the ground, who's job it was to watch for fires from inside the towing tractor. For unknown reasons the aircraft started moving forward, accelerating very quickly to a speed estimated around 60-70 km/h. The left wing struck the tractor, ejecting the occupant from the vehicle and causing him serious injuries. The aircraft continued forward in the direction of H4, when it entered a left turn. The aircraft eventually pirouetted 360 degrees, resulting in the port wing detaching from the fuselage at the leading edge and the port MLG getting push aft and inwards, embedding itself half-way inside the fuselage.
The occupant of the tractor is intensive care, in a medically induced coma, fighting for his life. Late 20s of age, with a pregnant girlfriend.