Families gathered at Ground Zero, the White House, Arlington National Cemetary, the Pentagon and a field in Pennsylvania for this morning's 9/11 Memorial.

Members of the House and Senate have filled the steps on the east front of the Capitol to honor victims of the Sept. 11, 2001 attacks.

Senate Democratic leader Harry Reid said the attacks failed to break the nation's will.

On the 11th anniversary of 9/11, Speaker John Boehner, becoming emotional with his voice breaking as he spoke, said Tuesday that greater good has come from Americans standing together shoulder-to-shoulder.

House Democratic leader Nancy Pelosi said that in the years to come, time will continue to tell the true story of 9/11: how the 9/11 families turned a national tragedy into a time of unity and how the nation came together.

Senate Republican leader Mitch McConnell said the greatness of America was revealed after the attacks, and

Obama: US safer, resilient on 9/11 anniversary

President Barack Obama and first lady Michelle Obama have paid a visit to Arlington National Cemetery and the graves of service members killed in Afghanistan and Iraq.

The visit to the burial ground across the Potomac River from the White House is part of the president's observance of the 11th anniversary of the 9/11 terrorist attacks.

The Obamas quietly walked between rows of graves at Section 60, which contains the remains of the most recent war dead. Pausing at several graves, Obama placed presidential "challenge" coins at the base of the headstones. The first headstone listed the names of 10 victims of an Oct. 26, 2009, helicopter crash in Afghanistan.

Earlier, the Obamas placed a wreath at the Pentagon and observed a moment of silence on the White House South Lawn.

Obama says the U.S. is safer and its people resilient, eleven years after the attacks.

Biden: Country hasn't forgotten 9/11 families


Vice President Joe Biden told loved ones of those killed 11 years ago on board Flight 93 that a ceremony in western Pennsylvania and others in New York and Washington, D.C. can be a reminder that the country hasn't forgotten them.

Biden participated in Tuesday's wreath-laying at the memorial where a United Airlines jet crashed in a field after passengers tried to wrest control of the plane from their hijackers during the terrorist attacks of Sept. 11, 2001.

Biden addressed about 150 family members and invited guests along with hundreds of citizens who began gathering before dawn in Shanksville, about 60 miles southeast of Pittsburgh.

The names of the passengers and crew were read aloud at 10:03 a.m., the moment the plane crashed.

Romney pays tribute to first responders

Mitt Romney has been marking the anniversary of the 9/11 attacks, first by greeting firefighters at Chicago's O'Hare Airport.

As he shook hands with the first responders, their yellow trucks formed a backdrop that recalled the sacrifice of the police and firefighters at ground zero.

Later today, Romney will be in Nevada to address the National Guard, whose members deployed as part of the military response.