Wreaths Across America, the nonprofit best known for placing veterans' wreaths on Arlington National Cemetery headstones, is asking every American to stand outside and wave a flag for one minute during four separate timestamps Friday, the 19th anniversary of the Sept. 11 terror attacks.

The organization is asking for the one-minute flag wavings to happen at 8:46 a.m., when hijackers crashed American Airlines Flight 11 into the World Trade Center’s North Tower; 9:03 a.m., when hijackers flew United Airlines Flight 173 into the World Trade Center’s South Tower; 9:37 a.m., when another five hijackers flew American Airlines Flight 77 into the Pentagon; and 10:03 a.m., when four hijackers crashed United Airlines Flight 93 into a field near Shanksville, Pennsylvania, after passengers began fighting back.

After the events of 9/11, Elaine Greene, Joann Miller and Carmen Foote were moved to find an old American flag they had stored at home and stand on a hill in Freeport, Maine, waving that flag to honor victims. These women became nationally known as “The Freeport Flag Ladies” and hoisted the Stars and Stripes every Tuesday morning for the following 18 years.

After they retired on Sept. 11, 2019, the following Tuesday, Sept. 17, 2019, Wreaths Across America took the helm and continued the weekly flag-waving tradition along U.S. 1 in Jonesboro, Maine, on land donated by the organization’s founder, Morrill Worcester, leading to the new Acadia National Cemetery.