"His friends are guarding the house. It's three or four of them have been at the house sitting in his room and at the table just wanting to be there for us," said Mack's uncle John Griffin III.
Overwhelmed with grief, Griffin told ABC11 his nephew was an exceptional swimmer who learned how to swim during preschool. The 20-year-old often taught his younger cousins how to swim while spending hot summer days at the family beach house in North Topsail.
"He swims in the ocean. He deals with rip currents. He's a swimmer. He's not somebody who doesn't know how to swim. To hear he drowned in a small lake with so much security is just shocking," said Griffin.
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According to Fayetteville Police, officers were dispatched to Lake Pines Swim Club Monday afternoon just after 3:15. Officers said Mack's body was found underwater near a diving board. CPR was performed until medics arrived.
The owner of Lake Pines Swim Club said there were 10 lifeguards on duty at the time with between 50 to 60 people in the water.
He said when lifeguards discovered Mack was missing they called his name multiple times over the PA system before jumping into the lake -- which is 16 feet at its deepest.
"To the family, I don't know if there are any words you can say to replace the fact that the young man lost his life. Terrible and tragic accident," said Lake Pines Swim Club owner Frank Lay.
Family told ABC11 that at 20, Mack was healthy and had a vibrant personality. He is also the grandson of Cumberland County's first African-American Superintendent, Dr. John Griffin II. Griffin said he and family members continue to hear from people who were swimming there that day.
"Everybody is sending me messages saying they were traumatized by the length of time as the emergency was going on. The length of time it took somebody to get in the water to look for him," said Griffin. "We were so busy planning for the future. We really just never thought this day would come."