A flag flies at half-staff above the White House after President Barack Obama made the proclamation to honor the victims of the shootings at the Washington Navy Yard on Monday, Sept. 16, 2013, in Washington. At least one gunman launched an attack inside the Washington Navy Yard, spraying gunfire on office workers in the cafeteria and in the hallways at the heavily secured military installation in the heart of the nation's capital, authorities said. (AP Photo/ Evan Vucci)