Recreational party triggered a small hard slab at the top of a steep rocky chute. Scrubbed to ground in the track and became a small size two. One of the group seemed to lose a ski. Observed the party of two on our ascent up the mellow benched terrain and came across the tracks on our exit in the afternoon. Not a great terrain choice given the current conditions and recent feedback to skier traffic in similar terrain in very close proximity. These two are very lucky to only lose a ski given the huge jaggered rocks they went for a ride in.