I was across Paradise River at the time and I looked over when I heard a crack and a falling noise. I saw the avalanche proceed down the slope. On Caltopo afterwards it looked like a terrain trap with a steep gully. We stayed away from that area for avy danger but it was close enough to easy access that people may not be aware of the danger and unintentionally be in the area exploring and be trapped. It had also been snowing for roughly 3 hours at that time.