Atlanta: An 18-year-old who had graduated from high school hours earlier drowned in Lake Allatoona this weekend while playing a game in which people launch someone off a dock in a shopping cart, authorities said. Chance Werner, of Euharlee, was playing the game with other teens and an adult at Dock D at the Holiday Harbor Marina in Bartow County just before midnight on Saturday. Witnesses said he had just graduated from high school on Saturday, authorities said.