A man working on an oil rig off the coast of Vietnam says he witnessed the missing Malaysian Airlines flight 370 burst into flames before falling into the ocean.

Mike McKay described the tragedy in an email to his supervisors and said he tried to contact authorities after it happened but no one ever responded.

“From when I first saw the burning (plane) until the flames went out (still at high altitude) was 10-15 seconds. There was no lateral movement, so it was either coming toward our location, stationary (falling) or going away from our location,” McKay wrote.

Several theories have been bandied about concerning the missing flight, including lost signals, pilots going off course, and one story about two passengers who were allegedly on board with stolen passports. However, officials are now no closer to finding answers than they were four days ago, when the plane was first discovered missing.

“At this stage in the investigation and search and rescue, I would have expected to see by now a much more defined understanding of what the route was, where the plane was headed and a narrowing of the search consequent upon that,” said CNN aviation expert Richard Quest.

The flight, which was carrying 239 people, has brought search parties out in the Gulf of Thailand since Saturday, but no clues have been found.

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