Immediately after applying takeoff power, the crew of the DC-6 heard a loud noise and the takeoff was abandoned. A visual check before the plane stopped revealed that the no. 4 engine had separated from the wing. A fire erupted and spread after evacuation, destroying the aircraft. It appeared that the no. 4 propeller had failed and that the unbalanced loads on the engine mounts caused separation of the entire engine. All crew and passengers survived but six dogs the cargo hold died in the accident. PROBABLE CAUSE: “The accident was caused by fatigue failure of No.1 blade of No.4 propeller. Laboratory findings showed that the failure was caused by previous blade bending resulting in the disruption of the compressive stresses in the shot peened area of the propeller blade.”