In 1996, TWA flight 800 exploded shortly after take-off from New York's JFK Airport instantly killing all 230 people on board. The scale of the disaster was enormous and wreckage was scattered all over the ocean. The families left behind needed to know exactly what had happened. There were three possibilities; mechanical failure, a bomb inside the hold or a missile from the outside. It soon became obvious that the explosion occurred inside the centre fuel tank, but what nobody knew, was the cause. After 12 months of the largest and most expensive airplane investigation to date, the FBI and NTSB revealed their verdict on the crash. They believed the fuel in the central tank had vapourised while the plane waited on the hot tarmac. A spark then ignited the vapours causing an enormous explosion. However, there is much speculation about the government's spark theory. Over 150 eyewitnesses claim they saw a rocket or missile strike the plane. Radar evidence and traces of plastic explosives found in the wreckage further added to the speculation. This programme speaks to all those involved in solving the mystery as well as key eyewitnesses and aviation experts in order to understand exactly what happened on that fateful day.