In public ceremonies and private reflections across the nation, and much of the world, people observed a moment of silence in remembrance of the nearly 3,000 victims of the September 11, 2001, terrorist attacks on the United States. The fifth anniversary may be the last one at the Ground Zero site.
Five years after the attacks, much of the focus of the commemorations was on New York where more than 2,700 people died when two hijacked airplanes crashed into the World Trade Center towers, shaking the United States' confidence and changing the New York skyline forever.
As at the previous commemorations at Ground Zero, family members read the names of the dead in a solemn ceremony against a sound track of somber and patriotic music.
Dozens of religious services and commemorative events took place around the city. At one, Mayor Michael Bloomberg said that as New York rebuilds, children must be taught more about the attack than the devastation it wrought.
"We must also share with them the beautiful memories of the loved ones we lost and of the incredible examples of courage we witnessed on that day," said Michael Bloomberg. "And most of all we must share with them our hope for the future, their future. That is how we will truly honor the memory of each of the 2,749 people we lost."
President and Mrs. Bush paid their respects on Sunday, placing a simple wreath on one of the reflecting pools at Ground Zero. They spent part of Monday morning at a firehouse near the site before traveling to the field near Shanksville, Pennsylvania, where 40 people died after wresting control of hijacked plane. The Bushes then returned to Washington and placed a wreathe at the Pentagon site where a fourth hijacked plane killed 184 people upon crashing.
Earlier in the day, Vice President Dick Cheney spoke during a memorial ceremony at the Pentagon.
"We have learned that oceans do not protect us, and threats that gather thousands of miles away can now find us here at home," said Dick Cheney.
The events of 9/11 were commemorated from coast to coast, from religions services in metropolitan cathedrals to makeshift memorials in small towns.
In California, Governor Arnold Schwarzenegger called for a return to the unity Americans experienced after the attacks.
"Let us remember the tragedy but also let us remember the triumph of the American spirit," said Arnold Schwarzenegger. "And let us return to the solidarity all Americans felt following those terrorist attacks."
The New York commemoration may have been the last one that will take place in the pit of Ground Zero as rebuilding for a new World Trade Center complex and a memorial is already under way. It is a sad prospect for Tania Garcia who lost her sister on 9/11.
"I know that the city needs to rebuild," said Tania Garcia. "I know that the city needs to keep up its status. I understand that people need to move on. But for me, I will never move on when it comes to this. This is somewhere where I will be for the rest of my life. This is a pain I will carry with me the rest of my life."
New York's international community also marked the day. At the United Nations, delegates observed a moment of silence. Secretary General Kofi Annan said "the attacks cut us to the core for they were an attack on humanity itself."
Britain remembered 67 of its own sons and daughters who died in the New York attack at a memorial garden in London. Americans and Russians joined together at a memorial service in Moscow.
In Helsinki, Finland, leaders attending the 38-nation Asia-Europe summit observed two minutes of silence, and a solemn military ceremony took place outside of NATO's headquarters. Bells tolled in Rome and in Germany, Pope Benedict celebrated a mass that included a prayer for world peace.
But the leaders of a number of nations, including US allies Germany and New Zealand, used the occasion to criticize the Bush Administration's war on terror as did newspaper editorials in Israel and Pakistan.