Usher - Usher's Stepson Dies 21 Days After Jet-ski Accident

The 11-year-old son of the singer's ex-wife Tameka Foster was declared brain dead by doctors after he was knocked out when an inflatable raft he was playing on collided with a watercraft driven by a family friend.

Glover and a 15-year-old female were airlifted to the children's healthcare unit at Atlanta's Egleston Pediatric Hospital. The girl reportedly suffered a cut to the head and a broken arm, while Glover took the brunt of the trauma to his head and slipped into a coma.

Stars including Whoopi Goldberg and Jamie Foxx have taken to Twitter.com to pay tribute to the youngster.

Goldberg writes, "Condolences Usher and Tameka Foster so sorry for ur (your) loss. My thoughts and prayers are with you," and Foxx writes, "My heart goes out to Usher and Tameka... for their loss."

Singer Toni Braxton tweeted, "My heart and prayers are with Tameka & Usher and their families. I'm sorry for your lost (sic), I'm here for both of you. From my family to yours."

Foster and other family members and friends took to Twitter following the tragic accident to ask fans and followers to pray for Glover.

His mother wrote, "We know God's in control, and (we) are leaning on our faith in Him and His word at this most difficult time. We firmly believe in the power of prayer and ask that you all continue to pray and lift Kile up, as it's the best way we can all support him now."

Local authorities launched an investigation into the incident and the jet-ski driver has been identified as family friend Jeffrey S. Hubbard. No charges have been filed.