A 21-year-old Central Gwinnett High School graduate drowned in Lake Lanier late Saturday afternoon after going into “distress” and submerging under the water, officials said.

Gwinnett firefighters responded to Buford’s Lanier Park shortly after 4 p.m. after receiving 911 calls about Lawrenceville resident Karon Antiwoin Jackson who had drowned, according to Gwinnett fire spokesman Justin Wilson.

Jackson graduated in 2015 from Central Gwinnett High School, where he played basketball. He earned All-Region 8-AAAAAA honors as a senior after the 2014-15 season.

“Friends of the victim stated they had swum out to the boundary of the beach area at the park and were returning to shore when the victim went into distress and under the surface of the water,” Wilson said. “Multiple bystanders attempted to assist the victim without success.”

The U.S. Army Corps of Engineers, who assisted on Saturday, said that although Lanier Park was open, the beach and swim area were closed to the public due to the lake’s high water levels.

While the Corps said a sign was posted saying the beach was closed, several local residents said that was not the case, and they were not informed that the beach was closed.

“Upon arrival, a park ranger was present at the gate and informed us there would be no charge for admission,” one woman told the Daily Post. “She stated the beach was not visible due to the water level and recommended we use the life vests provided at the beach for our 7-year-old.”

“Those guys were not swimming in a restricted area,” another man, who tried to help Jackson, said. “The beach was not closed at Lanier Park that day and in fact, the park attendant at the gate told me and everyone entering the park that day that Lanier Park was the only park that was in fact open for swimming.”

Wilson said when crews arrived on scene, they “gathered information on the location where the adult male victim went under the water” and swiftwater rescue technicians launched a rescue boat to find Jackson.

“The search for the victim under water was approaching one hour when a dive member from the Hall County Fire Service’s Marine Unit located the victim in approximately ten feet of water,” Wilson said. “The victim was removed from the water and transferred to the medical examiner on scene.”

Jackson’s former high school basketball coaches and friends took to Twitter to express their condolences.

“Such a sad day for me and all former Black Knights that had a chance to coach and play with this young man!! Prayers up for family and friends!!,” wrote David Allen, who now coaches basketball at Mill Creek.

Branden Mayweather, who now coaches at Lanier, wrote: “Life is so short and none of us are guaranteed anything. Take time to truly love and appreciate everyone, especially your family. There’s no doubt he made me a better person from knowing him.”

Officials from the Georgia Department of Natural Resources, Hall County Sheriff’s Office and Forsyth County Sheriff’s Office also responded to the scene on Saturday.