The 11-year-old died of heart failure, according to Channel 2 Action News.
Grammy award-winning singer Usher, whose real name is Usher Raymond, reportedly has remained close to his former wife and her family during the ordeal. He was also in the middle of a bitter custody battle with Foster over their two sons when the accident happened but has since soften some of his custody demands, according to media reports. The custody case is being heard in Fulton County court.
Condolences flooded social media Saturday. On his Facebook page, V-103 morning host DJ Frank Ski posted: "CRYING, I Will Miss You Kile! ... Sometimes Life Is So Unfair."
V-103's Greg Street tweeted: "Lil RG is an Angel now, Ryan, Tameka, Usher & the whole Glover Family we gotta make him proud!" Tweets of condolences also were sent by singer Justin Bieber, singer Toni Braxton, Def Jam co-founder Russell Simmons, singer Eric Benet, singer-actress Taraji P. Henson and many others.
"The investigation into this incident continues," DNR spokeswoman Melissa Cummings told The Atlanta Journal-Constitution on Saturday.
The DNR identified the man on the personal watercraft in the July boating accident as Jeffrey S. Hubbard of Atlanta, according to an incident report obtained by the AJC. The DNR has said that Hubbard and the injured children were part of the same group on an outing at the lake.
The DNR has said alcohol did not appear to be a factor in the incident, which happened in the mouth of Big Creeknear Holiday Marina.
Kile is one of two children born to Tameka Foster and Ryan Glover, her first husband. Glover is president of Bounce TV and a former executive with Turner Broadcasting.
Foster and Usher have two boys, 4-year-old Usher V (4) and 3-year-old Naviyd.
Staff writers Alexis Stevens and Jennifer Brett contributed to this report