Piggy in "Lord of the Flies" dies when a rock is thrown at him from a cliff, hitting him in the head and causing him to fall 40 feet to his death. The all-important conch shell, which kept order on the island and called the boys to meetings, shatters at the same time Piggy is killed.
In "The Lord of the Flies," Piggy represents the rational side of civilization. When Piggy is killed, all pretense of rational conduct is abandoned in the "society" established by the youth on the island. This reality is underscored with the boy's body washing out into the open sea after he is killed.