Explain Fitzgerald's use of the word "holocaust" in the last sentence of Chapter 8.
You may or may not be aware of this, but The Great Gatsby was first published in 1925, more than 20 years before we began to refer to the genocide of Jewish people in World War II as the Holocaust, with a capital "H." That holocaust had not yet happened, but the word has always been used with a small "h," too. The word has its origins in Middle English and meant something like "burnt offering." The modern use of the word is to describe great destruction or wholesale slaughter, particularly,but not necessarily, by fire.
What happened before right before Chapter XIII? Myrtle Wilson was killed by Daisy, who was driving Gatsby's car. Daisy did not stop, so this was a hit-and-run, basically a vehicular homicide. This is the beginning of a kind of holocaust.
If you look at the beginning of Chapter XIII, you will notice that the chapter opens with images of fire, Gatsby and Nick smoking. About halfway through the chapter, Nick refers again to the ashheaps and then the ashheaps are mentioned again when the scene shifts to George Wilson, who is drunkenly mourning his wife. Wilson has discovered that it was Gatsby's car that killed his wife. He believes that Gatsby was driving the car and that Gatsby was having an affair with Myrtle. He takes his gun, finds Gatsby's house, shoots Gatsby and then himself, thus completing the "holocaust."