Cornice failure avalanche

We approached the ridge with caution, snowboarder was practicing safe travel, sticking to the tree areas when attempting to push a small amount of cornice onto the Lee slope. It propagated up the ridge 70 meters or more.. 20 +m down the ridge from where the snowboarder was standing. The cornice failure picked up a fair amount of mass resulting in a sizeable avalanche. Cornice chunks up to the size of an oven. A lot of hang fire was left on this feature. The snow quality was dense deposited snow (4F- 1F). As per the picture, the run out of the avalanche stopped at the terrain feature 50 meters or so from the ridge top. We proceeded through the trees giving the cornice a wide birth. From the bottom we could see cracks that covered the whole ridge top. No one was injured or involved in the avalanche.