A 16-year-old girl suffered major head injuries and possibly a traumatic brain injury (TBI) when the Jeep she was a passenger in overturned in Nevada City. According to the California Highway Patrol, she was one of two passengers in a Jeep driven by a 17-year-old male. Alcohol is believed to be involved. Both the driver and the young girl were transported to Sierra Nevada Memorial Hospital in Grass Valley, CA. The third passenger, a 17-year-old male, was uninjured.