Looks like it was triggered by a snowmobile, just at the break of the ridge, Last weeks observations found that the old snow had faceted and we got a release of the of a small slab, much the same.
FORECASTER NOTE: This may have been snowmobile triggered or may have released naturally. I saw a similar cornice fall that fell naturally from recent wind loading. However, I also experienced a collapse of the snowpack under my machine in a drifted area. The collapse was due to the new drift sitting on old faceted (sugary) weak snow. Brett Kobernik