As a mark of respect for the victims of the Sept. 16 shootings at the Washington, DC, Navy Yard, President Obama has ordered that the U.S. flag be flown at half-staff at all federal facilities throughout the United States and its Territories and possessions until sunset, Sept. 20, 2013.

When flown at half-staff, hoist the flag to the peak for an instant and then lower it to the half-staff position. The flag should be raised to the peak again before it’s lowered for the day.