The United States has begun observing the ninth anniversary of September 2001 terrorist attacks. Bells tolled across New York to mark the moment at 7.16 PM Indian standard Time, when the first hijacked plane struck the North Tower of the World Trade Center nine years ago. The biggest event was in the city where relatives read out the names of 2975 people who died in the attack. US Vice-President Joe Biden and his wife were among the dignitaries who attended the commemoration in New York. For the first time, relatives reading out the names, have been joined by people working to build the Ground Zero memorial.New York Mayor Michael Bloomberg said, no other public tragedy has cut his city so deeply and no other place is as filled with their compassion, love and solidarity. Speaking at a memorial event at the Pentagon – which was also hit by an airliner on that day, President Obama paid tribute to those who died in the attacks, saying America's greatest weapon was to stay true to itself. Urging people to respect for other religious faiths, he declared that America will never be at war with Islam. He said, the US people will not sacrifice the liberties they cherish or take shelter behind walls of suspicion and mistrust. President Obama's wife Michelle, along with former First Lady Laura Bush, was present at the event in Shanksville, Pennsylvania, where another plane crashed apparently after the passengers fought with the terrorists. Meanwhile, the pastor behind the threat to burn Korans in Florida, has said, the event has been cancelled permanently.