WASHINGTON (AP) — President Joe Biden has marked the 21st anniversary of the Sept. 11 attacks, taking part in a somber wreath-laying ceremony held at the Pentagon under a steady rain. Biden paid tribute to “extraordinary Americans” who gave their lives on one of the United States’ darkest days. Sunday’s ceremony occurred a little more than a year after the Democratic president ended the long and costly war in Afghanistan that was launched in response to the terror attacks. Biden notes even after the U.S. left Afghanistan his administration continues to pursue those responsible for the 9/11 attacks. Biden announced in August the U.S. had killed an al-Qaida leader who helped plot the attacks.