On the morning of Sunday 27 December a snowmobile triggered a size 2.5 avalanche in the West Bowl of Mount Cain. The fracture line was investigated by a VIAC forecaster on 30 December and information was collected from observers who watched the event take place and who also examined a portion of the fracture line. The avalanche initiated from a steep, unsupported roll on the lookers left hand side of the bottom of the main gully in the west bowl, directly below the bottom of the ski line known as "Door Number Two". The failure plane was identified as surface hoar buried under a 60cm wind slab (in the location of initiation) that was 1 finger to pencil in hardness. The fracture then propagated uphill along the top of the steep unsupported lookers left side of the main gully for about 100m to the point where the gully widens. There the fracture crossed the gully and stepped down to layers of older windslab leaving a fracture line in excess of one metre high in places. The fracture continued to propagate down the lookers right side of the main gully releasing the lower portion of several of the gullies in the feature known as 'Sliders". The sledder reportedly just managed to ride ahead of the significant quantity of debris.