When I heard the news that Osama bin Laden was killed by U. S. forces in Pakistan, I had a lot of questions. And one of the people I wanted to talk to was Lawrence Wright. He's joined us several times on the show. He won a Pulitzer Prize for his 2006 book The Looming Tower: Al-Qaida and the Road to 9/11, which is based in part on more than 500 interviews, including interviews with friends and relatives of bin Laden.