The accident, the first drowning in Lake Allatoona this year, happened at the Holiday Harbor Marina, located at 5989 Groovers Landing Road in Acworth.
Chance Werner, of Euharlee, was among a group who were pushing each other into the lake in a shopping cart and kept playing the game by pulling the cart up with a rope.
Typically, the cart is tied to a pole at the dock. However, when Werner, who reportedly had graduated from high school earlier Saturday, went in, the rope was tied to his belt loop.
He was dragged down by the cart in about 30 feet of water and drowned. Department of Natural Resources personnel recovered him from the lake several hours later.
The incident is still under investigation.