Here is a compilation of crashes in the sport of cyclocross. Crashes happen often, but here is a quick view of what happens in the typical cyclocross race.
Remember, if you want to get into cyclocross, you can't be scared to crash. Crashing is part of the sport, so is getting back on the bike. So crash that bike, pick it up, wipe the mud off your face, jump on that bike, and do it all over again. Rinse and repeat, rinse and repeat.