October 29, 2018 - As a mark of solemn respect for the victims of the terrible act of violence perpetrated at The Tree of Life Synagogue in Pittsburgh, Pennsylvania, on October 27, 2018 by the authority vested in me as President of the United States by the Constitution and the laws of the United States of America, I hereby order that the flag of the United States shall be flown at half-staff at the White House and upon all public buildings and grounds, at all military posts and naval stations, and on all naval vessels of the Federal Government in the District of Columbia and throughout the United States and its Territories and possessions until sunset, October 31, 2018.
If you fly an outside flag that cannot be lowered respect can be shown by tying a black cord or ribbon to the top of the staff.
Read the proclamation here https://www.whitehouse.gov/presidential-actions/presidential-proclamatio...
Presidential Proclamation Honoring Victims of Tragedy in Pittsburgh
