By Tom Cohen, CNN
(CNN) - Amid solemn commemorations on Tuesday's 11th anniversary of the 9/11 terrorist attacks, President Barack Obama and other leaders emphasized how America has emerged stronger from the devastation that killed more than 2,900 people and forever changed the nation and the world.
"This anniversary allows us to renew our faith that even the darkest night gives way to the dawn," Obama said at the Pentagon, where 184 people died when one of four hijacked planes slammed into the iconic building symbolizing U.S. military might.
"As painful as this day is and always will be, it leaves us with a lesson that no single event can ever destroy who we are, no act of terrorism can ever change what we stand for," Obama said, adding: "When the history books are written, the true legacy of 9/11 will not be one of fear or hate or division. It will be a safer world, a stronger nation, and a people more united than ever before."
Earlier, Obama and first lady Michelle Obama stood with heads bowed and hands clasped on the White House lawn to observe a moment of silence at the exact time the first hijacked plane hit New York's World Trade Center in 2001.
White House staff stood in quiet observance on the grass behind them as a lone bugler played "Taps."