Why was the assassination of Franz Ferdinand so important

People believe its what sparked WWI. The story is actually very funny. Six assassins tried, one chichekend out, the other threw a granade, which bounced off the car and so he took an expired cynide pill and jumped intot he river. it was 6 inches deep, so he went to jail, and one was hungry, so he was ordering a sandwich, and Franz took a wrong turn, and so the assassin killed him. the rest of the assassins just gave up and went home. And thats the start of WWI