The United States is preparing for the ninth anniversary of 9 / 11 Terrorist Attack. About three thousand people lost their lives on this day nine years ago, when 19 hijackers of four airliners crashed the planes in to various targets. Two planes crashed into the twin towers of New York's World Trade Center, the site now named Ground Zero and one into the Pentagon, while the fourth crashed into a field in Pennsylvania, after passengers apparently fought back. A commemorative ceremony to mark the anniversary will be held this evening at Ground Zero. US Vice-President Joe Biden is to attend the official ceremony in New York at which the names of all the people who died at the WTC will be read out. Houses of worship across the city have been asked to toll their bells at 7.16 PM Indian Standard Time, the exact time the first hijacked plane struck the North Tower. President Obama will attend the ceremony at the Pentagon and his wife Michelle will attend the event in Shanksville, Pennsylvania, along with former first lady Laura Bush. Reports say, this years ceremony is likely to be the most contentious because of the controversy over plans for an Islamic centre near Ground Zero. The Florida pastor, who gave a threat to burn Koran to protest against the centre coming up there, has with held his threat. President Barack Obama has urged respect for other religious faiths after the threat, which sparked protests in Muslim World. In his remarks yesterday, Obama denied that his administration's intervention in the affair had elevated it to greater prominence. He appealed to Americans to respect the inalienable right of religious freedom and said such threats could add to the dangers facing US soldiers serving abroad. After the official commemorations are over, rallies are expected both for and against the proposed Islamic community centre and mosque near Ground Zero. Both sides want to use the emotion of the day to highlight their causes.