Silent Pass Sz 2.5

This is a third hand report based on information published on the Backcountry YYC Facebook group. Sz 2.5 avalanche (from pictures: ~100cm deep X 100 m wide X 300m+ long) triggered by snowmobile (?) Around 8,300 ft on NW aspect near Silent Pass. Airbag deployed and kept head above snow. Person okay. Deep persistent weak layer suspected as indicated by numerous rocks on the bed surface.