Wednesday night, I took the red-eye back to Boston, and wondered during the safety demonstration: would the passengers on board a commercial passenger jet really have much of a chance of surviving an emergency landing on the water?

Now I know the answer, thanks to Twitter: Yes, they would.

Last week a US Airways jet made a water landing on New York's Hudson River, shortly after departing from La Guardia Airport. I found out about it via a Wall Street Journal e-mail alert that was sent out at 3:52 in the afternoon, about 25 minutes after it happened, and immediately checked my regular breaking news sources. Nothing on Google News. CNN.com had a brief story that repeated the details of the WSJ alert, and a grainy screen capture from a local television news report, showing a partially submerged plane surrounded by boats. I followed the link through to the ABC affiliate but there was no live video or even an older video report.

But this is where it gets interesting.

My colleague in San Francisco IMed me a Flickr link. It was a mirror of a picture that had been posted to Twitter by someone on a passing ferry, and it told a story than the professional news organizations had thus far missed:

People had survived the crash. Scores were standing on the wing, or exiting one of the front doors into a gray rubber life raft, or the inflatable escape slide. I counted 34 on the wing, and 11 on the boat/slide. At least three of them were wearing what appeared to be the yellow life jackets stowed under the seats — the ones in the safety demonstrations that require passengers to connect straps and pull down a red tab or blow into a tube to inflate.

The picture was taken by Twitter user Janis Krums, who posted the picture to Twitpic. He was on the scene before the TV cameras arrived, and was able to inform Twitter users that people had survived, and rescuers were trying to pick them up ("There's a plane in the Hudson. I'm on the ferry going to pick up the people. Crazy.")

There was more Twitter information, too. Plane-related tweets accounted for eight of the ten top "trending topics" (Hudson River, MSNBC, US Airways, LaGuardia, etc.) Clicking through to them led to reaction of thousands of concerned people, and brief updates from some of them about what had happened, including references to reports that everyone had survived, and officials believed a flock of birds had been sucked into and disabled two of the plane's engines during takeoff.

Google News had nothing at that early stage, and even Google Hot Trends — which serves a similar function to Twitter's trending topics — had nothing on crash at first.

Of course, both of these Google services and the mainstream media caught up. But, Twitter was on the scene right away, and caught many details before any other media outlet or major online service.