Americans remembered 9/11 today with readings of victims' names, volunteer work, and other tributes 21 years after the deadliest terror attack on US soil.<br />''      <br />''  A tolling bell and a moment of silence began the commemoration at ground zero in New York, where the World Trade Center's twin towers were destroyed by the hijacked-plane attacks of 11th September, 2001.<br />'' <br />'' Victims' relatives and dignitaries also convened at the two other attack sites, the Pentagon and a field in Pennsylvania.<br />''      <br />''Other communities around the country are marking the day with candlelight vigils, interfaith services, and other commemorations. Some Americans are joining in volunteer projects on a day that is federally recognised as both Patriot Day and a National Day of Service and Remembrance.