VP Kamala Harris recalled the strong sense of unity that bonded America in the days following the September 11 attacks 20 years ago, calling it “essential to our shared prosperity” during remarks at the Flight 93 memorial in Shanksville, Pennsylvania. Back then, the world froze as four hijacked planes slammed into the World Trade Center, the Pentagon and a Pennsylvania field and brought nearly 3,000 people to their deaths. Lower Manhattan was torn to pieces, residents unsure if it would ever recover. Washington was under attack. Americans were terrified. Global markets plunged. In the two decades since, foreign policy has been upended. Security measures at global borders, airports and office buildings reshaped travel and international business. New York City was transformed. The echoes of the destruction wrought on 9/11 -- and what it took to rebuild after -- haven’t been lost on those gathering Saturday at Ground Zero, resounding the message by New York Governor Kathy Hochul: “We never forget, but we go forth into the future steeled in the conviction that yes, we were knocked down, but we are never out. Whether it’s a terrorist attack, whether it’s the pandemic.” Hochul joined President Joe Biden, the Obamas, the Clintons and other U.S. officials at the National September 11 Memorial & Museum to read the names of those killed in the attack. The annual reading is held by the nonprofit, chaired by former New York City Mayor Michael Bloomberg, the founder and majority owner of Bloomberg LP, the parent company of Bloomberg News. U.S. Defense Secretary Lloyd Austin, an Afghan war veteran, paid tribute to the 184 people killed when a hijacked plane hit the Pentagon, saying “we do know that America will always lead.” “We must be tireless guardians of our ideals, as well as our security,” Austin said in remarks at an outdoor ceremony at the Pentagon attended by Vice President Kamala Harris, President George W. Bush and Interior Secretary Deb Haaland. “Because we cannot have one without the other.” He recalled that President Franklin Roosevelt gave a fireside chat on Sept. 11, 1941 -- before the U.S. entered World War II -- to rally Americans against the global threat of fascism. Roosevelt’s call for “clear heads and fearless hearts” is valid again today, Austin said.