IT IS too early to speculate, but in the absence of a distress call, investigators looking into the sudden disappearance of the Malaysia Airlines' (MAS) Boeing 777-200 plane over the South China Sea are already working on two distinct theories - a catastrophic electrical failure or a mid-air explosion.
Ominously, the plot has thickened since it was discovered that at least two men, an Italian and an Austrian, who were listed among the 239 passengers and crew, both had their passports stolen more than a year ago and are still very much alive.
There have been two cases of airline sabotage in Asia over the past four decades - the crash of a Cathay Pacific Convair 880 in Vietnam's Central Highlands in June 1972 and the downing of a Korean Air Boeing 707 over Myanmar's Gulf of Martaban in November 1987.
I covered both, first as a young Bangkok Post staff member and later as a Far Eastern Economic Review correspondent in South Korea.
The circumstances may have been different, but both produced the same tragic result, taking the lives of 196 innocent passengers and crew.
In some ways, there is an eerie similarity between the Cathay Pacific case and the MAS incident.
Flight 700Z took off from Bangkok bound for Hong Kong. It was only a few minutes of flying time from the Vietnamese coast when it went down in an active war zone.
The two British air crash investigators sent to the scene by helicopter quickly found a jagged hole punched in the central fuselage and other telltale evidence that showed a bomb had exploded in the cabin at 29,000 feet, causing the plane to break into three distinct parts as it plunged into the jungle below.
Investigators Vernon Clancey and Eric Newton knew something about sabotage. Five years earlier, in an amazing piece of detective work, they had determined from a single waterlogged cushion floating in the Mediterranean that a bomb had brought down a British Airways jetliner off the Isle of Rhodes.
The two men told me in an interview back then that cushions and bodies were "wonderful for collecting things".
In that disaster, they were dust-size fragments of metal, not normally found in an aircraft, which were calculated to have been travelling at a velocity of 10,000 feet per second.
The Cathay Pacific bomber erred in his timing. Any later and the plane would have vanished into the South China Sea, where it would have been difficult to recover.
Over the next few weeks, suspicions began to centre on Thai police lieutenant Somchai Chaiyasutr after it was discovered that the blast had gone off under the window seat occupied by his 20-year-old common law wife, who was taking Somchai's seven-year-old daughter on a shopping trip.
The evidence piled up. Somchai had insured the two victims for 5.5 million baht. He had bought C4 plastic explosive from a fellow policeman. He had holes bored in a cosmetics case the waitress had carried aboard the plane.
On an earlier guided tour of a Thai International DC 8, he had asked about the most vulnerable part of an aircraft. He had boarded the ill-fated flight before departure and made a fuss about ensuring his wife and little girl were seated over the wing.
He had shown virtually no remorse.
But despite what appeared to be his overwhelming guilt, the Thai court acquitted him of the sabotage charges in May 1974, perhaps guided by military strongman Prapat Charusathien's emotionally nationalistic claim that a loving Thai father would never kill his daughter for money.
I was there for the 2 1/2-hour reading of the verdict. It was like a boxing match, with onlookers standing on tables, chairs and benches cheering and shouting.
No one seemed to understand or care what a travesty of justice it was. Thailand's version of the O.J. Simpson trial.
Somchai sued for and received all the insurance money, but he didn't live long enough to enjoy the proceeds.
In 1983, two years after he resigned as a newly promoted police colonel, he died of liver cancer at the age of 43. I have often thought it was the hand of God.
Later, in 1987, when Korean Air flight 858 disappeared from radar screens for unexplained reasons over Myanmar's Gulf of Martaban, the South Korean government seemed to know almost instinctively that it was the work of North Korean saboteurs.
In October 1983, North Korean agents had triggered a bomb at a mausoleum in Yangon, killing 21 people, including three South Korean Cabinet ministers, but missing its intended target, President Chun Doo Hwan, who had yet to arrive for a wreath-laying event.
The two Korean Air bombers, who had placed the device in an overhead storage bin before leaving the flight in Abu Dhabi, were quickly traced to Bahrain. The male agent killed himself with cyanide, but his companion, Kim Hyon Hui, was overpowered before she could follow suit.
Flown back to Seoul, a mouth gag in place to prevent her chewing off her tongue, Kim was initially given the death penalty.
But she was later pardoned after it was decided that she had been brainwashed into taking part in the bombing, which she claimed had been personally ordered by then North Korean leader Kim Jong Il.
"I deserved the death penalty for what I did, but I believe my life was spared because I was the only witness to this terror perpetrated by North Korea," she said in an interview last year. "As the only witness, it is my destiny to testify about the truth."
Today, the truth of what befell MAS flight MH370 on its six-hour flight to Beijing might well depend on the sort of technological advances that should allow specialised underwater vehicles, such as that which Singapore possesses, to recover critical parts of the aircraft's wreckage.
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