It was a deep snow immersion. No tree well. Just snow so deep she got buried, couldn't free herself and suffocated. Scary. I guess this has happened one other time with this operation. During a previous owners watch. This is a tough one to pin down.
Probably a lot like quicksand in this case. Once she got under the snow she was probably unable to clear it out to breathe. Add an ice mask once covered and you don't have long. I will try to watch out for the final report on this one. It is scary stuff indeed.
You'll get a small taste of it at Jay, Polonia. Even falling into 3 or 4 feet of snow with your head downhill and loaded conifers overhead is enough to make you nervous. Compare that with BC where you can have 20 foot tree wells and incredibly deep pow and it's easy to see how a person can get into trouble.