On February 8, 2009, Rihanna and her then-boyfriend, R&B star Chris Brown, got into a heated argument while driving home from a pre-Grammy party. According to police reports, the argument escalated into a violent attack. Chris was arrested for assault and pleaded guilty. Now, Rihanna opens up to Oprah about the night she says she lost her best friend. Plus, find out why Rihanna felt protective of Chris despite her anger.