Despite all the fears and conspiracy theories, the conclusion is ``inescapable'' that an explosion of vapors in a fuel tank is what brought down TWA Flight 800 four years ago.

Despite all the fears and conspiracy theories, the conclusion is ``inescapable'' that an explosion of vapors in a fuel tank is what brought down TWA Flight 800 four years ago at a loss of 230 lives, a top federal investigator concluded Tuesday. Investigators ``cannot be certain'' what ignited the blast, but the most likely cause was an electrical short in wiring inside the tank, said Bernard S. Loeb, aviation safety director of the National Transportation Safety Board. The physical evidence, he said, ``leads to the inescapable conclusion'' that the plane was brought down by a fuel-air explosion inside the center wing tank. As the meeting wore on, Robert Swaim of the aviation engineering section expressed the frustration of investigators seeking the source of ignition. ``I would love to walk in here with a molten piece of wire and say, 'Here it is,''' he said. Loeb said there was no evidence that metal fatigue, corrosion, recent repairs of the plane, a bomb or a missile was involved in the disaster off the coast of New York's Long Island. The Boeing 747 crashed on July 17, 1996, shortly after taking off from John F. Kennedy Airport in New York en route to Paris. Investigator James Wildey of the NTSB's materials laboratory explained that the explosion originated in the huge fuel tank located where the wing spars pass through the plane's center. The tank was partly empty and air conditioners located beneath the tank had given off heat, warming the fuel during a long wait for takeoff.