Ouch!
My wide-angle lens took a bit of abuse. Fortunately, the filter took almost all of the impact, although a bit of the cladding around the outer lens element did get knocked loose. Note the assymetric dent where the lens impacted the rock. (Update: I managed to clean everything out and cut off the wrecked filter, and re-attached the fascia piece that detached, and the lens seems ok... whew!)