NEW YORK - Families of the victims of the worst terror attack on the United States in history gathered Wednesday to mark their 12th anniversary with a moment of silence and the reading of names.
The Sept. 11, 2001 attacks in New York City and Washington killed almost 3,000 people, led to a long war in Afghanistan and created an expansion of government surveillance powers that continues to be debated today.
At a ceremony near Wall Street in New York, people paused at 8:46 a.m. to mark the time when the first of two hijacked planes struck the World Trade Center. The twin towers later collapsed.
President Barack Obama also marked a moment of silence at the White House and was attending a ceremony in Washington at the Pentagon, which was struck by another hijacked plane.
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The attacks on a clear, beautiful morning as commuters arrived at work shook the country's sense of security and of itself.
"Twelve years is like 15 minutes," said Clyde Frazier, whose son Clyde died in the attack and whose remains were never found. "Time stands still because you love your child, you love your son. ... Nothing changes except he's not here."
Obama on Wednesday made no direct mention of the crisis in Syria, but he vowed to "defend our nation" against the threats that endure.
"Let us have the wisdom to know that while force is sometimes necessary, force alone cannot build the world we seek," Obama said during a ceremony at the Pentagon.
The president also paid tribute to the four Americans killed one year ago in an attack on a U.S. compound in Benghazi, Libya, asking the country to pray for those who "serve in dangerous posts" even after more than a decade of war.
In New York, continuing a decision made last year, no politicians were making speeches.
Around the world, thousands of volunteers have pledged to do good deeds, honoring an anniversary that was designated a National Day of Service and Remembrance in 2009.