The TWA crash on July 17 was one of many of tragic, horrifying, plane crashes in 1996. It seemed the year had more than its share, and a study released in December proved that true. More people were killed on commercial flights in 1996 than any other year. It isn't that air travel has become less safe, the study said, but that there are far more flights now, and that increases the odds of a crash.
The TWA crash received the most news coverage because in addition to the horror of crash and the anguish of relatives waiting for recovery of bodies from a vast underwater grave, there was the unanswered question: Why did the plane explode? And with that mystery came the suspicion that it was bombed or shot out of the sky.
The search for an answer was given secondary priority after the search for the bodies of the 230 victims. Divers spent more than three months hunting the Atlantic off Long Island and managed to find remains of all but 16. The body of one of the pilots was found still strapped to his seat. The last body was found in October, by a fisherman trawling the ocean floor.
Some of the saddest images of the summer involved the victims' possessions, or their grieving relatives. Clothing, souvenirs, letters and postcards were found floating on the ocean surface. Relatives held a memorial service on Fire Island, off Long Island, the closest they could get to where the plane went down. They walked sadly along the shore, tossing their flowers and bouquets to the waves.
The crash was a puzzle, literally. Each recovered piece was trucked to a hangar, where the Boeing 747 is being meticulously put back together. A wing, a row of seats, an engine, the mangled remnants of the cockpit -- "a mass of spaghetti," the head investigator called it.
When they finally stopped on November 2, Navy crews had scoured hundreds of miles of ocean, diving 3,200 times -- one of the biggest salvage efforts in U.S. history. They had recovered 95 percent of the jumbo jet. And still, five months later, the question lingered: Why did the plane explode?
From the beginning, investigators carefully listed all possibilities as equal: mechanical failure, a bomb, or a missile. They repeated the litany day after day, but most believed it was sabotage. It was unlikely, experts said, that a plane could explode without warning because of mechanical trouble. And what was that mysterious streak of light some witnesses said they saw heading for the plane? Some speculated it might have been a missile.
Security at airports was tightened. The start of the Olympics in Atlanta was just weeks away.
Then came what seemed like the proof: On August 23, residue of chemicals used in explosives was found on a piece of debris. But a few weeks later came surprising word that five weeks before the crash, small amounts of explosives had been hidden on the jet to test bomb-sniffing dogs. Investigators said the residue might have originated from those tests.
Another theory came via the Internet. A document circulating on e-mail -- source unknown -- said the plane was the victim of "friendly fire" -- accidentally shot down by a Navy warship. The media didn't take it seriously until Pierre Salinger, a former ABC News correspondent and President John Kennedy aide, reported it. The FBI called the document "absolute, pure, utter nonsense," but Salinger stuck to his guns.
When no firm evidence of sabotage was found, mechanical failure became the prevailing theory. Investigators now suspect an explosion of vapors in the center fuel tank, possibly sparked by static electricity. On December 13, the National Transportation Safety Board said it had found a flaw in the fuel-system piping of 747's that could cause such an explosion. The safety board issued an urgent recommendation that the problem be corrected, but did not conclude it was the cause of the TWA explosion. "The law enforcement team is not ruling out a bomb or a missile," chief criminal investigator James Kallstrom said.
Lacking a piece of definitive proof, investigators hope the answer lies in the hangar in Calverton, Long Island. It will take months more to put together the 92-foot long midsection of the jet, now in thousands of pieces. They hope that once that's done, like a puzzle, an image of what caused the jet to explode will appear.