The boy's death
When a motorcade accidentally kills an innocent child, that is the spark in the powder keg. The death of any random person might have set off a serious consequence, but the death of an innocent child? That's enough to rip the town apart. The boy's death becomes the rallying cry for the rioters on one side, and when that community takes its vengeance by killing innocent people, both sides have enough fuel to stay at war for a long, long time.
The revenge killing
The most symbolic aspect of the revenge killing where the African American men cornered and assassinated an innocent man was that he was innocent. He was a scapegoat whose death was literally an attempt to sate a blood-thirst. This innocent victim proves something nether-worldly about the riots. These riots are not just about getting even, so to speak. They are full-blown explosions of wrath where people's dark side will be unleashed.
The unnecessary enemies
To each party, the other side became "The Enemy." But they aren't necessarily enemies at all. If they coordinated, they would easily learn that they have been driven into conflict because of a scarcity of resources that has its roots in systemic injustice. They could cooperate to bring about real change through peaceful demonstrations. Their willingness to point the finger at the other person turned what should have been a constructive moment in history and turned it into a hellscape of tragedy, death, and destruction.
"Us and Them"
Since these factions split off based on appearance, and since they took vengeance so wantonly, the battles quickly spiral into a conflict of "Us and Them." This is a critical aspect of the riots. This is another good reason not to judge based on skin color; when the "enemy" is someone easily recognizable and different in appearance than one's own self, it becomes easy to become hateful and wrathful against people one has never met, simply because of their skin color. This is what makes race riots so difficult to quell once they begin.
The negative example for change
This story is not one that cries out to be emulated. This is one of those narratives that says, "Let's never do this again." Why should communities of oppressed minorities be driven into warfare when they could be cooperating to combat real injustice in a meaningful way, through non-violent ways that don't destroy the community? This is a necessary allegorical lesson that would potentially be applicable today, especially when gang warfare splits communities.
