What happens to piggy in Lord of the Flies?

Piggy is made fun of throughout the book because he is fat and has "Ass-mar" (Asthma). They also use his glasses to start fires and Jack breaks them at one point. No one lets him talk at any of the meetings either. Eventually the kids split into two tribes and they end up stealing and breaking his glasses. Then, Ralph and some other kids go to get them back and the other tribe pushes a large boulder on top of piggy killing him and breaking the conch.