In the immediate aftermath of the terrorist attacks of September 11, 2001, people across the country and around the world reacted with shock and grief, while authorities in the U.S. acted swiftly to secure public buildings and landmarks seen as potential targets, in case another incident was yet to come.

In Seattle, authorities evacuated downtown skyscrapers and closed federal buildings. Traffic at Sea-Tac came to a halt as airports across the country shut down. The Space Needle was evacuated and access roads leading to it blocked to traffic. Seattle Center closed most of its other buildings as well and cancelled all events.

This image shows the Space Needle after the terrorist attacks on September 11, 2001, with an American flag flying at half-mast at top. A partly lowered flag also flies on the Two Union Square Building, at left.

Caption information source: "Swift response in Northwest" by Margaret Taus, Seattle Post-Intelligencer, September 11, 2001, p. 8.