Chapter 13 is entirely about pathos. Chris's family was struck extremely hard by the news of his death, and it is clear through the chapter that they have still not come to terms with the tragedy. Chris's parents, Billie and Walt, and his sister Carine, all showed their grief in different ways. Through their anecdotes, the reader sees how important Chris really was to them, and how much they loved him despite his personal eccentricities. Carine even speaks about how her appetite changed due to the loss, connecting it with Chris's last days:
"I just couldn't bear the thought of throwing away food since Chris had starved to death." Over the weeks that followed, however, she found that her appetite had vanished...
Back in Chesapeake Beach, Billie had stopped eating, too... she lost eight pounds before her appetite finally returned.
(Krakauer, Into the Wild, Amazon.com)
As Carine mentions, their loss of appetite served as a grim reminder of Chris's cause of death. To waste food while Chris starved was unthinkable, and yet the mental rationalization could not overcome the physical sickness that often follows a great tragedy. With small stories like this one, and the expression of grief in their own words to underline their feelings, this chapter shows pathos at its most raw.