Remembering the Boston Marathon Bombing; Digital Journalism; Biz Stone

One year after the Boston Marathon bombing, former Boston Globe columnist Mike Barnicle and runner Joel Steinhaus reflect on the response to the tragedy. A conversation with journalists Bill Keller of The Marshall Project, Nate Silver of ESPN's FiveThirtyEight, and Kara Swisher and Walter Mossberg of Recode, who have left established news organizations to pursue digital ventures. Twitter's co-founder Biz Stone on various projects--including the Jelly app--and his new book, "Things a Little Bird Told Me: Confessions of the Creative Mind."