I saw the aftermath of this avalanche later in the day.
The avy observation is correct - we were actually sitting at the Pizza Factory next to the party who wrote and posted the report that evening.
We were lucky that we hiked through this section at 5 AM, when it was still cold. The avy happened in late morning, a few hours of warming after the sunrise.
From what I heard, the slide came down near a party of four. There was one person partially buried and injured his foot/leg. A party of two were able to shield themselves behind a large boulder, and then came out to dig up the buried victim. Another party came along (there were 5 of them I believe, they wrote the avy report) and stayed with the injured person until the rescue chopper picked him up around 530 PM. A SAR ground team also came to help. That is a long time to wait to be extracted - keep that in mind when planning your outings!
The North Fork of Lone Pine Creek has very steep rock walls on both sides between 9000-10000 feet. It's a huge terrain trap and the slabs aren't going to hold the snow much longer as the days get warmer and the nights are not cold enough for refreezing below 9000-10000 feet or so. There is water running between the rock and the snow on top of it, undermining the snow and creating a layer of lubrication. Point releases and wet slides were prevalent below, at, and above treeline, on all aspects.
Everyone was lucky on Saturday - this could have happened to any of us. When going out in these conditions, please wear a beacon, probe, shovel, and first aid gear - and know how to use all of these things! Take an avalanche class and Outdoor Emergency Care (OEC) or Wilderness First Aid course.
The slide path and debris. The avalanche crown is visible on the right side of the dark rock in the center. That entire rock was covered in snow/ice that slid.
Size of debris ranged from microwave- to refrigerator-sized chunks
