Mr. Weiss talked about his book, The Man Who Warned America: The Life and Death of John O’Neill, the FBI’s Embattled Counter-Terrorism Warrior, published by HarperCollins. He described the life of John O’Neill, who repeatedly warned the U.S. government about future attacks by Osama bin Laden, and who believed the World Trade Center would be a target. After quitting the Federal Bureau of Investigations due to conflicts within the agency, Mr. O’Neill was hired as head of security for the World Trade Center in early September of 2001. He was killed during the September 11, 2001, attacks while helping survivors in the south tower. Mr. Weiss answered audience members' questions after his presentation.