Holy cow! I've never trusted carnival rides and I've always been a bit apprehensive about amusement parks in general, so this video doesn't calm my nerves much!
Watch the top of the screen, you can see the rider come out from under the ride, then get flung over the ride and finally you can hear her hit the guard rail.
When the video picks up again, you can see the huge dent/bend in the gate- although I'm not sure she caused that damage it sure seems like she would have!
Oh and do you want more? check out this website: www.RideAccidents.com