Complex sentence: It was immediately renewed for a second season of 10 episodes to begin airing in January of 2013, however on March 14,2012, the show was canceled by HBO after three horses died during production.
Split into simpler sentences: It was immediately renewed for a second season of 10 episodes to begin airing in January of 2013. On March 14,2012, the show was canceled after a third horse died during production.