On July 17, 1996, TWA Flight 800 took off from John F. Kennedy airport in New York for Paris, only to fall from the sky minutes later. At first, the cause of the crash was a mystery, spawning a slew of conspiracy theories. After a painstaking reconstruction of the Boeing 747, investigators determined that a fuel tank had exploded due to an electrical spark. For years, the reconstruction has been used as a teaching tool for air crash investigators. But now, it’s being dismantled for good.