What shatters the conch and Piggy in "The Lord of the Flies"?
In a literal sense, a huge rock dropped from a great height shatters the conch and Piggy. Piggy is holding the conch and trying to persuade the boys to return to living in a civilized manner, while Roger stands above, dropping stones on him. Finally, "with a sense of delirious abandonment", Roger, using a lever because of the killing instrument's size, releases a "great rock" upon Piggy, causing the conch to explode "into a thousand white fragments", and striking Piggy "a glancing blow" which results in him falling forty feet onto a rock in the sea below to his death.
In a symbolic sense, it is the final and complete descent into savagery on the part of the boys which shatters the conch, which represents order and lawfulness, and Piggy, who, without his spectacles, is its blind adherent. At the moment of his death, Piggy, in a last, desperate attempt to appeal to the group's better nature, entreats, "Which is better...to have rules and agree, or to hunt and kill?" His words are drowned out by shouting and yelling, inaudible to the tribe of boys who have rejected civilized behavior in favor of anarchy and lawlessness. As the killing stone hurtles down upon him, Piggy stands impotent, "still holding out the talisman, the fragile, shining beauty of the shell" in the face of a "storm of sound...and the incantation of hatred" (chapter 11).