The contact who is a State Trooper reported that the driver of a 2024 Jeep Grand Cherokee was fatally injured when a second vehicle crashed into the rear of the vehicle. A witness reported that the vehicle had stopped in the left eastbound lane on [XXX] when a second vehicle traveling approximately 70 MPH crashed into the rear of the vehicle. During the crash, the driver was partially ejected from the closed sunroof. The driver was pronounced deceased at the scene. The driver of the second vehicle was transported to the hospital with multiple fractures. No further information was available. The contact indicated that medical personnel removed the deceased driver from thru the sunroof of the vehicle and no doors had opened during the crash. While investigating the crash the contact reported that the steering wheel had separated from the steering column and was located near the rear seat area. Also, there were no visual signs of damage to the steering column or any sheered-off bolts from the steering column present. The contact indicated that an eye witness also indicated that the vehicle was driving erratically prior to stopping. The vehicle was later towed away. The cause of the incident was not determined. The manufacturer and local dealer were not yet contacted. The failure mileage was unknown.