Oh I've seen bigger and I can tell you the story behind it too. I don't remember the year but there was a lake in one of the lower States. It had a salt mine in a nearby hill that extended under the lake and an oil platform on top of the lake. The platform accedently drilled through one of the salt mine tunnels and the entire lake drained in little more then a half an hour. It was quite the thing to see.
-X