Head Gamemaker Seneca Crane's luck runs out after his mis-managment of the 74th Games leads to Katniss and Peeta manipulating the game and its audience in order to both survive. As a result, President Snow orders him to be locked in a room which contains only a bowl of Nightlock berries. It's initially left ambiguous as to whether Crane decided to eat the berries for a quick death or starve himself, but in Catching Fire, it's mentioned that he "decided to stop breathing", and Katniss creates a crude effigy of him hanging himself during her presentation to Plutarch. It's not like he didn't deserve it, but damn, that's cold...