Usher's 11-year-old stepson Kyle Glover is in critical condition after a boat collision outside Atlanta, Georgia.

A man in a jet ski hit a boat pulling Glover, 11, and a 15-year-old girl riding in a inner tubes at Lake Lanier on Friday afternoon. Alcohol was not a factor in the accident, according to a Department of Natural Resources spokesman.

The children were air lifted to Children's Healthcare at Egleston Hospital, and a source told that Glover remains unresponsive and is in critical condition.

Glover is the son of Usher's estranged wife Tameka Foster. The singer reportedly chartered a plane for Foster to be by her son's side.

This is third boating accident at the lake this summer. In June, the Prince brothers of Buford were killed during a collision. Also last month a youth nearly lost his leg in an accident involving a boat propeller.

It's been a difficult couple of months for Usher. He recently got a restraining order against a woman who claimed she was his wife