"Many people climb Mt. Rainier every year without incident, and the route taken by the parties hit by this slide is attempted annually by about five percent of all climbers."
i'm not going to challenge the accuracy of the above statistics, but wanted to offer some context to the point made above. Ingraham glacier is one of the mainstream routes to the summit. A group of my friends who i regularly climb with just returned from Mt. Rainier and summited via the same route three weeks ago. All the guided parties who started from Camp Muir went up the Ingraham Glacier route as well. it is the preferred route before the snow melts and exposes the crevasses, at which point navigation is difficult and DC becomes the most preferred "easy" route. The problem with emphasizing the 5% statistic above is that most guided and tourist oriented trips happen in the summer, via DC. Otherwise, it is a very normal route during the early season, and is considered pretty basic. The point i'm trying to make that this could happen to any party, experienced, guided, independent and what not. If it's not an avalanche, it could be a serac crashing down you, rockfall, crevasse fall... These same real risks are present and they affect anyone venturing out in high altitude regardless of route, season or ability. Something to be aware and accepting of if you choose to pursue this activity.