The contact owns a 2016 Ford Expedition. While parked in her friend's driveway with her child in her car seat, the contact heard an abnormal, popping sound as she was outside of the vehicle. The vehicle began to roll back without warning with her child inside the vehicle; she attempted to hit the emergency brake but was unsuccessful. The vehicle continued to roll backward into a neighbor's fence before the vehicle came to a halt. The contact's daughter was safe inside the car seat and did not sustain any injuries; however, the contact sustained mental trauma as a result of the failure. A police report was filed due to the neighbor's damaged fence. The vehicle had yet to be diagnosed or repaired for the failure. The manufacturer was notified of the failure and the contact was given a case number; she was then referred to NHTSA for additional assistance. The failure mileage was approximately 100,200.