No one who was there or watched it on TV will ever forget the rioting in Los Angeles that began 20 years ago this Sunday. The mostly-black community of South L.A. erupted after a jury acquitted four white police officers in the videotaped beating of Rodney King, a black motorist stopped for speeding. Six days of violence killed 55 people, injured thousands, and shocked the nation. CBS News correspondent John Blackstone covered the riots in 1992 and returned to the neighborhood this week. When Los Angeles was seized by chaos and violence 20 years ago, the city's deep divisions were...