Usher's 11-year-old stepson, Kyle Glover, has been declared braindead following a jet ski accident.
Kyle was hit in the head by a jet ski in Georgia, reportedly driven by a family friend, and was unresponsive when taken to hospital.
He has still not regained consciousness and has "not experienced any brain activity" since.
A source close to Usher told HollywoodLife.com that the rapper is "completely devastated and shaken with what has occurred".
Kyle's mother and Usher's ex-wife, Tameka Foster, wrote on her Facebook page, "Kyle, You are strong ... You'll be saved I know it. I love you my baby. I need all #Prayers for my son! thanks you everybody!"
A decision is currently being made about whether or not to keep Kyle on life support. Officials have declined to comment further on his condition.