Why Hung Cao is trending

<p>Secretary of the Navy John Phelan was fired from his position Wednesday, according to sources familiar with the matter, with Undersecretary Hung Cao replacing him as Acting Secretary of the Navy. CNN's Brian Todd breaks down what led to Phelan's ouster. Discover more videos, including live streams and exclusive storytelling, on our <a href="http://cnn.com/watch">Watch</a> page.</p>