(NBC News) Today marks the 12th anniversary of the September 11th terrorist attacks that killed nearly three thousand people.
Remembrance ceremonies are taking place around the country.
The largest, is in New York City at the site of the fallen World Trade towers, where friends and families of the victims gathered.
Church bells marked the time of the first attack on the north tower of the World Trade Center.
Families and friends of the victims stood in silence on hallowed ground where twin reflecting pools now mark the memorial plaza now in the place of ground zero.
President Obama also participated in this moment of silence, from the White House.
When the bells stopped relatives began reading the names of the nearly three thousand victims aloud.
For Jay Winuk, who lost his brother, Glenn, in the attacks on World Trade Towers its hard to believe 12 years have passed.
"Sometimes it feels like yesterday," Winuk said.
Jay is among the hundreds of relatives returning to ground zero to take part in a private remembrance ceremony set beside the twin reflecting pools on the memorial plaza.
As in years past, moments of silence will mark the times of each attack and relatives will read the victim's names aloud.
Even as this ceremony stays constant the space around ground zero continues to change.
One World Trade Center now stretches into the void left by the fallen towers.
It will be finished early next year and by spring the 9-11 museum will also be complete.
"It was this museum where we are going to educate people on years to come," said Joe Daniels, president of the National 9/11 Memorial and Museum.
The sacred space will be a lasting record of the tragedy's 12-years ago today forever connecting ground zero to the attacks at the Pentagon, where the President will speak at a memorial today.
In Shanksville, Pennsylvania, visitors began gathering yesterday to mark the start of construction on a new visitors' center.
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