later, a fire warning led the crew to believe that a fire had erupted in the forward cargo hold. They then discharged at least one bank of the fire extinguisher bottles in the forward cargo hold. Because they did not follow the correct procedure, the cabin pressure relief valves were closed. This caused hazardous concentrations of the gas to enter into the cockpit. These concentrations reduced the pilots to a state of confused consciousness probably resulting in loss of consciousness. An emergency descent was initiated until it described a shallow left turn, heading towards constantly rising terrain. Five miles east of Shamokin, the airplane, flying only 200 feet above the ground, entered a right climbing turn. As it passed to the north of Mt. Carmel, the climbing turning attitude increased sharply. The airplane then crashed in a power line clearing on wooded hillside at an elevation of 1,649 feet. The airplane struck a 66,000-volt transformer, severed power lines, and burst into flames. Investigation revealed that the fire warning in the cargo compartment had been false. — CAB File No. 1-0075-48 The CAB concluded with the following probable cause for the accident: "The Board determines that the probable cause of this accident was the incapacitation of the crew by a concentration of gas in the cockpit." See also Centralia, Pennsylvania List of accidents and incidents involving commercial aircraft TWA Flight 513 United Airlines Flight 608 References External links Final Report - Civil Aeronautics Board - PDF Aviation accidents and incidents in the United States in 1948 1948 in Pennsylvania Airliner accidents and incidents in Pennsylvania Airliner accidents and incidents caused by pilot error Airliner accidents and incidents caused by in-flight fires Airliner accidents and incidents caused by pilot incapacitation 624 Accidents and incidents involving the Douglas DC-6 History of Columbia County, Pennsylvania June 1948 events in the United States