You can probably assume what would happen if a grizzly bear decided to hang out at your campsite, but to actually watch what happens on video is pretty good confirmation of what you suspected would happen!
Check out this footage, posted by the Billings Gazette on YouTube, taken at ZooMontana while grizzly bears, Ozzy and Bruno, demonstrate the damage bears can do to a campsite when campers do not take precautions against bears:
