A 38-year-old man who was in the group was riding a jet ski in the same area and the jet ski collided with Glover and the woman on the inner tube. Both were airlifted to a local hospital.
As of July 7, the boy was still in critical condition following the incident. Officials say that alcohol was not a factor in the accident and it is still too early to tell if charges will be filed.
Usher, whose full name is Usher Raymond IV, and Foster are involved in a bitter custody dispute over the former couple's two children, 4-year-old Usher Raymond V and 3-year-old Naviyd Ely.
The singer filed for divorce in June 2009, claiming that the couple had lived separately for nearly a year of their two year marriage. Their divorce was finalized in November 2009 and the two were in court for a custody battle in May.
Usher signed his first recording contract when he was 14 years old, with "X-Factor" judge L.A. Reid. His debut album was released in 1994 and featured co-executive producer Sean "Puffy" Combs. The seven time Grammy-winner has put out seven albums in total, including his upcoming release, "Looking 4 Myself," which was released on June 12.