Fire crews arrived and found a white 1991 Mazda Navaho SUV on its roof in the southbound lanes. Three passengers were found at the scene, with one discovered trapped inside the vehicle. Firefighters worked for approximately 15 minutes to free the trapped occupant. 

The SUV had been driven off the right side of the roadway when it struck a guardrail and overturned. It slid upside down a short distance on Highway 63 before coming to a stop.

The driver of the car, 24-year-old Zachary K. Schouten of Columbia, and one passenger, 34-year-old Shannon D. Merritt of Columbia, were transported to University Hospital with moderate injuries and are currently in stable condition. Laura J. Wells, the other 39-year-old female passenger, was partially ejected from the vehicle and pronounced dead at the scene by staff from the Boone County Medical Examiner's Office.

Officials believe alcohol and/or drugs contributed to the accident and are continuing to investigate.