Cinna is the stylist for Katniss Everdeen in the Hunger Games. He is killed by the Capitol's peacekeepers during the uprising in Mockingjay.
He is killed during a bombing in the Capitol, a scene that is particularly heartbreaking and impactful. The loss of Cinna is a major turning point in the story, as it further fuels Katniss's anger and determination to fight against the Capitol.