wheel hub bearing worn defective

I bought my 2014 Nissan Versa Note in July 2014 with 22 miles on it. In April 2015 I began noticing a strange rubbing noise when making slow, sharp left turns. Took it into the Nissan dealership and it turns out that both wheel hub bearings on the front had worn defective for no apparent reason. This in turn caused damage to the brake rotors, which were replaced along with the brake pads. I was not given any explanation as to how this could have happened in a brand new car. I have never been in any accidents and I drive carefully. Of course I might have hit a pothole from time to time, but that's no excuse for a part like this to break so soon. Nissan replaced the parts as everything was still under warranty, but still makes me nervous as to why something like this happened in such a new car.