Avalanche: Turnagain

We (Party 1) were digging a pit in lower angle terrain near the looker's left flank of the avalanche. We did not see or hear it release. As we were finishing digging our pit two skiers (Party 2) came down to us and reported that they thought they might have triggered an avalanche. We popped out of the pit, looked south and saw debris. They also reported seeing two other skiers (Party 3) in the area. They were pretty sure they were not in the path of the avalanche but couldn't confirm their whereabouts. They skinned back up to see if they could locate them and we went towards the debris pile. We both went to search with our beacons. One stayed in a safe spot and the other went out onto the debris to check for a signal. While out on the debris, contact was made with Party 3 and we confirmed they were ok. They skied down to us and reported that one of them had ski cut across lower angle terrain and saw cracking and the avalanche release down the ridge. The avalanche propagated around three separate terrain features on the ridge and connected. From the road it looked like three separate avalanches. It ran approximately 600ft along the ridge and 200-500 ft down the slope. Blocks of debris were 4' high. The debris was approximately 3-6' deep. The avalanche was definitely large enough to bury, injure or kill a person.