Usher's 11-year-old stepson has passed away this morning from injuries suffered in a tragic jetski accident in Georgia earlier this month ... TMZ has learned.

According to our sources, Tameka is understandably devastated.

Glover was injured on July 8 ... as he was riding in an inner tube that was connected to a pontoon in Lake Lanier. According to authorities, a family friend who was riding a jetski behind the pontoon lost control and collided with Glover's tube.

The accident is currently under investigation.