The contact's son owns a 2025 Honda Accord. The owner stated that while coming to a stop, the brake pedal was depressed, but the vehicle failed to stop. No warning light was illuminated. The owner fully lifted the foot from the brake pedal and forcefully depressed the brake pedal while attempting to stop the vehicle. The vehicle failed to stop, causing the contact's son to rear-end a semi-truck. The contact's son stated that the vehicle powered off after the crash. The contact's son also stated that the air bags did not deploy during the crash. The vehicle was taken to the dealer, but the failure was not diagnosed or repaired. The dealer informed the contact that the failure could be duplicated. The manufacturer was made aware of the failure by telephone, and the contact was corresponding with a case manager via email. A case was opened. The failure mileage was approximately 14,000.