At 7:52 p.m., a nanny called police and alerted them that the boy was missing. Minutes later, multiple 911 calls reported a child pedestrian had been hit by a vehicle in the area of Jamboree Road and Portola Parkway, according to the Tustin Police Department.
Emergency responders arrived at the scene and found the victim unresponsive, police said. He was transported to Children's Hospital of Orange County, where he succumbed to his injuries.
The driver of the vehicle, an adult male, remained at the crash site and was cooperating with investigators, according to the police department.
Neither speed, drugs nor alcohol were involved, investigators said, adding that the boy ran across the center divider and into traffic lanes before he was hit.
An investigation into the incident is ongoing.