Ice ice baby

Rider 2 triggered a small slab avalanche (approx 10” deep, 20ft wide and 10ft long) on a steep west facing sidehill when exiting the area they were riding in. The slab was on top of an icy layer. There were no signs of instability on the route in or when rider 1 took a lower line on the way out ahead of rider 2. Dangers were noted and all three riders leap frogged out of the area to the trees.