Fell off his broom at about sixty feet. As if the wind and rain weren't bad enough, the Dementors crashed the party. Harry must have blacked out again, like he did on the train. Of course, with so many people watching, there were at least twenty wands all pointed at him to try to slow his fall, but he was blowing around in the gale so much that it was only party successful.

To make matters worse his broom hit the Whomping Willow. It, er, doesn't like to be hit. You may remember.