Doctors declared Usher's 11-year-old stepson, Kyle Glover, brain dead after a weekend watersport accident in Georgia, TMZ reported.
The boy is the son of the singer's ex-wife Tameka Foster and her ex-husband Atlanta-based clothier Ryan Glover.
Usher and Foster were married from 2007-09 and have two sons together.
Kyle was critically injured when he was struck in the head by a passing personal watercraft while riding on an inner tube on Lake Lanier in Atlanta.
TMZ said he had not exhibited any brain activity since being admitted to the hospital but no decision had been made about whether to take him off life support.
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