I've noticed a pattern developing over the last three texts, and that is the tendency for the narrators to start of their story on a relatively downtrodden note. Krakauer's first chapter is the summit, where he begins to foreshadow the later events of the narrative. Bancroft's book begins with a chapter entitled "Hell". Blum ends her opening chapter by talking about how she would rather stay behind with her boyfriend. Why do these adventurers choose to open on such a foreboding note?
In the case of Krakauer at least, the answer is pretty obvious: he wants to introduce the tragedy that will shortly (in terms of pages as well as chronological time within the text) come to pass. The entirety of Krakauer's book had a very macabre feeling. I kept looking back at the dedication page to see which of the characters involved, the ones I was growing attached to and rooting for, would not survive the descent. It would have arguably been more dramatic if Krakauer had tried to keep the narrative more lighthearted up until the point when disaster struck, but I do not believe the text would have conveyed its message as effectively. In the end, when Krakauer gives the statistics for death tolls on Everest, I wasn't comforted to know that the Spring of 1996 was in fact bellow the typical ratio (I believe it was 1:4 on average, but 1:7 for that season), because Krakauer had kept up a negative outlook on the whole expedition from the first pages of the text.
It's a little more difficult to justify these downer openings in Bancroft and Blum. Blum at least has a bit of a negative hue (in that two members of the climb were killed), but Bancroft's text seemed entirely positive and uplifting. Perhaps the intent of the author (or maybe the editor?) was to demonstrate how there was nowhere to go but up from that point in their expedition, to get the negativity out of the way for the most part so that the narrative could focus on the positive outcome of their journey.