Witnessed this avalanche slide while unloading from the crest chair at Brighton around noon. It was triggered by a snowboarder who was not carried. It appeared to break under their feet as they were essentially left sitting on the crown after the slide (which appeared to be roughly a foot deep). The snowboarder then stood up and rode out the slide path. I alerted ski patrol stationed at the access gate. Hopefully patrol will provide you with additional information/photos.