The American flag is flown at half-mast, sometimes referred to as half-staff, to commemorate the deaths of government figures, members of the armed forces and other distinguished citizens or groups of citizens. By federal law, only the president of the United States and the governors of the various states and territories have the authority to give an executive order to fly a flag at half-staff.
Federal law stipulates that the flag should be flown at half-staff for 30 days after the death of a president or former president; for 10 days after the death of a vice president, chief justice or speaker of the House of Representatives; from death until the internment of an associate Supreme Court justice, secretary of a military department, former vice president or state governor; and for two days after the death of a member of Congress. The flag is flown at half-staff yearly for Memorial Day, Patriot's Day, National Firefighters Memorial Day and Pearl Harbor Remembrance Day. When a flag is flown at half-staff, it is first raised to full peak and then lowered to half-staff position. It is again raised to the peak before being taken down for the day.
Special dignitaries for whose deaths presidents ordered the flag to fly at half-staff include Winston Churchill, Anwar Sadat, Yitzhak Rabin, King Hussein of Jordan, Pope John Paul II, Nelson Mandela, Rosa Parks, Coretta Scott King and Ted Kennedy. Presidents also ordered the flag to fly at half-staff to commemorate the victims of the Space Shuttle Columbia crash, Hurricane Katrina, the Virginia Tech massacre, the Fort Hood massacre, the Sandy Hook Elementary School shootings and the Boston Marathon bombings.