The contact owns a 2016 Ford Edge. The contact stated that while driving 65 MPH on the interstate with the rear windshield defroster engaged, the vehicle made an abnormal, loud popping sound, and the contact noticed that the rear window had shattered. The contact drove under an underpass, switched lanes, and pulled over safely. There was no warning light illuminated. The contact called the local dealer, who confirmed that the VIN was not included in a recall. The vehicle was inspected by a glass specialist who secured the rear windshield with plastic. The specialist determined that the rear window defroster had been overheating. The vehicle was not repaired. The manufacturer was contacted and referred the contact to the NHTSA hotline for assistance. The failure mileage was approximately 98,009.