Our party of four toured in Mill A basin today. As we approached, we discussed current avalanche conditions and read the avy forecast for the day. We started with low angle safe terrain but our over confidence and complacency led us to steeper and more dangerous terrain. We ascended the ridge that separates Mill A basin from Maxfield basin with the plan to ski back down into Mill A basin. The line we chose was a 40 degree north east facing run (bulls eye for avalanches under current conditions) that starts in pines high on the ridge but opens up and leads down to lower angle aspens. I'm still wondering why all four of us thought this idea was ok. The first skier made two or three turns when the slope on both the right and left of him broke and started to slide. The skier was next to a group of pines and was able to grab onto a small tree as the slab slid by most likely saving his life. The crown was 2 feet, it propagated several hundred feet horizontally and traveled approximately 800 feet down into the aspens. The four skiers descended the slide path and conducted a beacon search of the debris pile in case of other unknown parties potentially ascending the skin track below possibly buried. There were no signs of any other party present.

*Forecaster note - there is a suspicion this avalanche could have failed on buried surface hoar from 2/9.