Americans across the country came together on Sept. 11 to commemorate the 20th anniversary of the 9/11 terror attacks that killed nearly 3,000, wounded thousands more, and left an indelible scar on the nation’s psyche. Observances were planned across the country—from a wreath-laying in Portland, Maine, to flags flying at half-staff at the Washington Monument—marked by a sea of statues, 9/11 plaques, and sorrowful Americans vowing never to forget the deadliest act of terrorism on U.S. soil. A ceremony at ground zero in New York City got underway with a first responder striking a silver bell at 8:46 a.m., the exact time when the first of two hijacked planes crashed into one of the World Trade Center’s twin towers. “It felt like an evil specter had descended on our world, but it was also a time when many people acted above and beyond the ordinary,” said Mike Low, whose daughter, …