NEW YORK (CNN) -- Thousands of mourners -- many carrying pictures of loved ones killed two years ago during the terror attacks unleashed on the nation -- gathered Thursday in New York to honor those killed that day.
At Ground Zero, streams people lined up at the site where the twin towers of the World Trade Center once stood. One woman clutched a picture of her son that bore the words, "We will never forget you. My son I love you."
Bagpipes played "Amazing Grace" shortly before a moment of silence was observed at 8:46 a.m. EDT, the time when American Airlines Flight 11 hit the north tower of the World Trade Center -- the first of four hijacked planes used as missiles that day.
Besides the two planes that hit the trade center towers, planes crashed into the Pentagon and in a field outside Shanksville, Pennsylvania.
About 200 children whose relatives were killed in the attacks then began reading the names of the 2,792 victims of the World Trade Center attacks. They will pause three more times to mark the times when United Airlines Flight 175 hit the south tower and when the two buildings collapsed.
New York Mayor Michael Bloomberg called Thursday "a sad day, but we're going to get through this."
"The future for New York City is quite bright," Bloomberg told CNN. "We are in a fight together. It's not just New York and the rest of the country. It's really New York and the rest of the world."
He added: "The president is right on this one: We have to strike back."
Rudy Giuliani, the former New York mayor who was hailed as a hero for his leadership during the attacks and days that followed, used the second anniversary to call for a better memorial for those lost that day.
He called current designs wrong "because the concept emphasizes office buildings, not the significance of the place."
"When you see that design, the first thing that should capture you is the importance of what happened there -- the memorial aspect of it," he told CNN.
The design, he said, should provide a "tremendous amount of respect ... for the final resting place of a couple thousand people who will never recover and are buried there at the bedrock."
Giuliani said the nation must never forget what happened on September 11, 2001, which Congress declared Patriot Day after the attacks.
"I see it as the worst evil perpetrated on our country and basically which was challenged by some of the greatest good that we are capable of. It's something we have to keep reminding ourselves of," he said.
New York Gov. George Pataki, looking at the thousands gathered at Ground Zero, said the "sense of loss is like it happened yesterday."
"I don't think that sense of sorrow will diminish, but at the same time, you can't help but feel pride," Pataki said. "You look down and see the firefighters, you hear the bagpipes. You see the people, and you have a tremendous sense of pride [in] the heroism and courage that New Yorkers showed on September 11."