** ADVANCE FOR SUNDAY JULY 16 ** FILE ** FBI agents and New York state police guard the reconstruction of TWA Flight 800 in Calverton, N.Y., in this Nov. 19, 1997, file photo. Federal investigators determined that ten years ago TWA 800 was destroyed by a fuel-tank explosion, likely caused by a spark from a short-circuit in the Boeing 747's wiring that ignited the tank's vapors. But conspiracy theories that say the plane was blown up by a terrorist's missile or the U.S. government have persisted over the past decade - even among some family members. (AP Photo/Mark Lennihan)