The contact owns a 2015 Subaru Outback. The contact stated while driving at 20 mph, the brakes would not engage as the brake pedal was depressed. As a result, the vehicle rear-ended a parked vehicle on the side of the road. The air bags failed to deploy. A police report was not filed. Three of the passengers in the vehicle sustained head and neck injuries that required medical treatment. The vehicle was drivable and was taken to a local dealer where it has been for 5 months. The vehicle was diagnosed with nothing needing to be replaced. The manufacturer had been informed of the failure and referred the contact to the dealer to have the engineers look at the vehicle. The failure mileage was 56,000.