Avalanche control work at Mt Baker the end of March 2012 resulted in this 3-5 meter crown as measured by patroller Peter Moran. The avalanche risk was 2/3 (moderate). The bombing shows there is still a deep and still active fragile layer in the snow pack which may cause some releases when temperatures rise. A snow profile showed an icy bed (hence the rope) with a layer of faceted snow.
We don’t see many slabs like that in France but here is a photo from the Grand Sablat, l’Alpe d’Huez back in 1987.