The contact owned a 2025 Tesla Model X. The contact stated that while driving at approximately 65 MPH with Self-driving Assist activated, while the vehicle in front deaccelerated, the vehicle had aggressively deaccelerated. The contact stated that the self-driving assist had deactivated, causing him to aggressively depress the brake pedal, stopping before it struck the vehicle in front. Several unknown warning lights illuminated. In addition, the contact stated that the vehicle was struck in the rear by another vehicle, causing the vehicle to rear-end another vehicle. The contact sought medical attention for head and back injuries. A police report was filed. The vehicle was towed to a local dealer, where it was deemed a loss. The manufacturer was made aware of the failure. The failure mileage was approximately 6,150.