The 9/11 anniversary commemoration at ground zero began Saturday with a tolling bell and a moment of silence, exactly 20 years after the start of the deadliest terror attack on US soil. The anniversary comes under the pall of a pandemic and in the shadow of the US withdrawal from Afghanistan, now ruled by the same militants who gave safe haven to the 9/11 plotters. The attacks killed nearly 3,000 people and marked the start of a new era of fear, war, politics, patriotism, and tragedy, per the AP. "It's hard because you hoped that this would just be a different time and a different world. But sometimes history starts to repeat itself and not in the best of ways," says Thea Trinidad, who lost her father in the attacks and was set to read victims' names at the ceremony at ground zero in New York. More on the somber tributes and messages as the day progresses: