A screening of the HBO Documentary "Sergio" preceded by a conversation with: Samantha Power, Senior Director for Multilateral Affairs, NSC and Greg Barker- Director and Producer of the Documentary. Filmmaker Greg Barker's Emmy-nominated documentary tells the inspiring story of dedicated humanitarian Sérgio Vieira de Mello, his final mission as United Nations ambassador to Iraq and the deadly bombing of U.N. headquarters in Baghdad on August 19, 2003. Through first-person testimony, chilling film footage and gripping reenactments, Barker's film chronicles the day of the terrorist attack and the attempts to save Vieira de Mello.