R&B superstar Usher's 11-year-old stepson Kile Glover has been declared brain dead following a jet ski accident that left him in critical condition on Friday, according to TMZ.

The Atlanta Journal-Constitution reported Friday that an 11-year-old boy and a 15-year-old girl were riding in an inner tube pulled behind a pontoon boat on Lake Lanier in Atlanta when a 38-year-old man on a rented personal watercraft struck them. The boy, later identified as Usher's stepson, sustained more severe injuries than the girl; he was unresponsive after being pulled from the water.

Glover is the son of Usher's ex-wife Tameka Foster. Though she and the singer are currently embroiled in bitter custody negotiations over their two sons, Usher Raymond V, 4, and Naviyd, 3, TMZ reports that Usher chartered a plane to Atlanta for Foster, who was out of town when the incident occured, and joined her at the hospital.

The Atlanta Journal-Constitution stated that alcohol does not appear to be a factor in the incident.

[TMZ / Atlanta Journal-Constitution // Image via Getty]