Usher is said to be "torn up" over the jet ski accident Saturday that has left his 11-year-old stepson Kyle Glover in critical condition.

Despite his acrimonious split with ex-wife Tameka Foster and their custody battle over their two children; Usher V, four, and Naviyd, three, Usher is said to have remained close to Kyle.

Us Weekly reports that the 33-year-old singer is devastated and doing all he can to help.

"He grew close to Kyle and, of course, that has nothing to do with the situation with Tameka," a source told the publication.

"He loved Kyle. This is a terrible, awful tragedy. Usher is torn up."

"Tameka and Usher don't get along, but in this circumstance Usher is coming to her side. Usher practically raised Kyle as his own. He's known him for seven years. It is so sad what happened."

Kyle is in an Atlanta hospital after being struck by a 38-year-old man on a jet ski at Lake Lanier while he and a 15-year-old were being pulled along on an inner tube by a speedboat.

TMZ reports that doctors have now declared that the young boy is brain dead. Usher and Tameka divorced in 2009 after two years of marriage.