On this week's "60 Minutes," evidence of Syrian President Bashar Assad and his regime's legacy of war crimes. Scott Pelley reports on the effort to gather and maintain evidence against President Assad, for the acts of terror he perpetrated against his own people during Syria's civil war. Ten year after a powerful earthquake and tsunami caused a massive nuclear meltdown in the Daiichi Power Plant, Lesley Stahl reports on the unprecedented cleanup efforts. And two-time Pulitzer-winner Colson Whitehead opens up to John Dickerson about his writing process, his wide variety of interests, getting rejected and "the space of very little hope" he found himself working in when he wrote "The Underground Railroad" and "The Nickel Boys."