The 11-year-old stepson of megastar singer Usher has been declared brain dead after a jet-ski accident on Atlanta's Lake Lanier, TMZ reports. Kyle Glover, the son of Usher's estranged wife Tameka Foster, was hit in the head by the watercraft while floating in an inner tube. A 15-year-old girl he was with also suffered serious injuries. Officials say the man on the jet ski was part of the same group as the children, and alcohol does not appear to have been a factor in the accident. Usher and Foster are both present at the hospital, where there has been no decision yet on taking the boy off life support.