The Marion County Coroner's Office says Dylan Williams died of blunt force trauma Thursday, two days after suffering the injury in Union City, about 75 miles northeast of Indianapolis.
Coroner's office manager Marchele Hall tells The Indianapolis Star an autopsy showed the injury occurred on the right side of the boy's head and neck.
The boy was hit by a ball that had been thrown during practice Tuesday evening. He was taken to a hospital in Winchester, then transferred to an Indianapolis hospital.
Union City Fire Chief Gary Moore tells The (Muncie) Star Press that organizers of the baseball program were arranging help and counseling for other children who witnessed the accident.