U.S. President George W. Bush and other top officials joined thousands gathering across the country Sunday in tributes, prayers and quiet reflection on the eve of the fifth anniversary of the September 11 terrorist attacks. In New York, the president and first lady Laura Bush placed wreaths in pools of water where the World Trade Center's twin towers stood before two commercial airliners toppled them five years ago. Other memorials were held in Washington, where another hijacked passenger plane slammed into the Pentagon, and in Shanksville, Pennsylvania, where a fourth jet crashed into a field, CNN reported. An estimated 2,973 people were killed in the attacks.