Symbolism, Imagery, Allegory
So maybe Tod is a prophet, after all. As predicted by his painting "The Burning of Los Angeles," the riot that closes the novel represents "the people who come to California to die" finally expressing their feelings of disappointment.
The riot occurs right on the heels of the Faye-Miguel incident. Tod is getting some fresh air when he stumbles across a disturbed-looking Homer, who "walked more than ever like a badly made automaton and his features were set in a rigid, mechanical grin" (27.23). Though Tod tries to get him away from the crowd, Homer ends up releasing his anger at Faye on the young Adore Loomis after the kid tries to play a trick on him. And so begins the riot.
Interestingly, Tod later hears people saying that the riot was started when a "a pervert attacked a child" (27.61). Sounds like they're talking about Homer, but that's not at all what happened. To add another layer of irony to this, Tod actually does see a pervert assaulting a child that night and tries to save her, though the poor girl is ultimately scooped up by another rioter.
To us, this whole scene illustrates the disappointment at the core of this particular kind of life. As Tod says, the masses have been conditioned to expect excitement and violence, so when they see Homer attacking Adore, they immediately assume the worst. That gives them the perfect excuse to vent their frustration. Furthermore, Homer is the perfect target for this repressed anger, as his simple-minded innocence makes him an easy scapegoat for the disappointed masses.