The crash happened at about 12:45 p.m. on a dirt road on private property at 27308 Fairview Ave. just north of Hayward, Perea said.
According to initial reports, it appears the boy was driving the vehicle down a hill when he lost control and the vehicle began to roll over. The boy may have been partially ejected from the vehicle as it tumbled, Perea said.
The boy was taken to a hospital, where he died from his injuries.
The Alameda County Sheriff's Office first responded to the call, but once it was determined that the incident involved a vehicle, the CHP was called in to investigate, Perea said.
The cause of the crash is still under investigation. The CHP will be inspecting the vehicle to see if any mechanical problems could have caused the crash, Perea said.
Perea said so far it appears to be "a horrible, tragic accident."