One person is dead and roughly 70 others injured after a Singapore Airlines flight headed from London to Singapore hit severe turbulence yesterday.

The Boeing flight with 211 passengers and 18 crew on board descended 6,000 feet in the

span of three minutes over the Indian Ocean, forcing the plane to make an

emergency landing in Bangkok where rescue crews were on the tarmac ready to

assist the injured.

In a statement today, Singapore Airlines offered condolences for the deceased and said, quote,

we deeply apologize for the traumatic

experience that our passengers and crew members suffered on this flight. Our

aviation correspondent Miles O'Brien joins us now. So, Miles, pilots and air traffic control can often detect and avoid turbulence.

What seems to have happened here?

Well, in some cases they can, Jeff, exactly.

If you see some storm systems

storm systems ahead towering cumulus clouds which generate

thunderstorms and perhaps worse prudent pilots and air traffic

control will change the course of the aircraft to thread their way around it.

It's still unsettled air, however, and so there can be a lot of turbulence in a region,

particularly if you're trying to thread your way through

those big build-ups.

But there is another category of turbulence, which could be at play here, called Clear Air

Turbulence, which really does come quite literally out of the blue.

And this can occur when you have rivers of air.

The jet stream is kind of like a river of air, except that it's wind at, you know, sometimes hundreds of miles an hour.

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