Approx 20 hits before depth hoar began to sluff away below shovel. After digging pit, we traversed skier's right approx 50 feet and experienced a collapse and cracking of the new snow slab sitting on top of a buried surface hoar layer. No surface hoar noted in the pit we dug at this exact location. We observed ECTP 11 and ECTP 6 on the buried surface hoar layer at the location of the collapse and cracking. We descended down the ridge to the lower angle terrain skier's right of the burn area.