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.

“This is a tragedy for this young man just as he was starting the next stage in his life,” said Melissa Cummings, spokeswoman for Georgia Department of Natural Resources.

Werner and two other young men were pushing each other into the lake in the shopping cart, and pulling the cart back up with a rope, according to Bartow County Sheriff Clark Millsap.

Typically when people play this game, the cart is tied to a pole at the dock, but in this instance, Werner decided to act as the pole, Cummings said. The rope was tied to the cart and his belt loop, she said.

When the cart was pushed off the dock, it dragged Werner down into about 30 feet of water and he drowned, she said.

DNR officers patrolling the lake were called to the dock at 12:07 a.m. Sunday. Bartow County police and fire also responded. The body was recovered at 2:50 a.m. Sunday.

“We don’t want people playing games with water like this,” Cummings said. “It’s an accident waiting to happen — kids playing with ropes and heavy objects.”

This is the first drowning of the holiday weekend, and the first in Lake Allatoona this year, she said.