MANHATTAN - (AP) -- Tears in her eyes, firefighter widow Maureen Fanning emerged Thursday from the new Sept. 11 museum deep beneath ground zero, unable to bring herself to look at all of it.
"I just think it would be a little too overwhelming today," she said, unsure when she would return. "It's a lot to digest, to absorb. Not anytime soon."
Victims' friends and relatives, rescue workers and survivors of the terrorist attack descended into the subterranean space and revisited the tragedy as the National Sept. 11 Memorial Museum was dedicated by President Barack Obama as a symbol that says of America: "Nothing can ever break us."
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The museum's artifacts range from the monumental, like two of the huge fork-shaped columns from the World Trade Center's facade, to the intimate: a wedding ring, a victim's voice mail message.
Some relatives found the exhibits both upsetting and inspiring.
Patricia Smith's visit came down to one small object: the New York Police Department shield her mother, Moira, was wearing 12½ years ago when she died helping to evacuate the twin towers.
Patricia, 14, said she left feeling a new level of connection to her mother. Still, "seeing that, reading the story that goes along with it, even if I already know it, is really upsetting," she said.
David Greenberg, who lost a dozen colleagues who met for breakfast at the trade center's Windows on the World restaurant on Sept. 11, called the museum "breathtaking, awe-inspiring and emotional."
"You have your moments when there can be solitude, moments when there can be happiness, and a mixture of emotions through the entire museum," said Greenberg, who worked at an office nearby.
The museum opens to the public Wednesday, but many of those affected most directly by 9/11 could start exploring it Thursday.
Family members also paid their first visits to a repository at the museum that contains unidentified remains from the disaster.
Monika Iken never received her husband's body. "But he's here. I know he's here," Iken, a museum board member, said after leaving the repository.
Many in the audience wiped away tears during the dedication ceremony, which revisited both the horror and the heroism of Sept. 11, 2001, the day 19 al-Qaida hijackers crashed four airliners into the trade center, the Pentagon and a field in Pennsylvania. Nearly 3,000 people were killed in an attack that plunged the U.S. into a decade of war in Afghanistan against al-Qaida's Taliban protectors.
After viewing some of the exhibits, including a mangled fire truck and a memorial wall with photos of victims, Obama retold the story of Welles Crowther, a 24-year-old World Trade Center worker who became known as "the man in the red bandanna" after he led others to safety from one of the towers. He died in the tower's collapse.
The president said the museum pays tribute to "the true spirit of 9/11 -- love, compassion, sacrifice."
"Like the great wall and bedrock that embrace us today," Obama said, referring to the way the foundation withstood the attack, "nothing can ever break us. Nothing can change who we are as Americans."
One of the red bandannas Crowther made a habit of carrying is in the museum. Crowther's mother, Alison, said she hoped it would inspire visitors to help other people.
"This is the true legacy of Sept. 11," she said.
Former President George W. Bush was also invited, according to the museum. But Bush spokesman Freddy Ford said he was unable to attend because of a scheduling conflict.
At the dedication ceremony, retired Fire Department Lt. Mickey Cross described being trapped for hours in the wreckage -- and then joining the recovery effort after being rescued.
Kayla Bergeron remembered taking her final steps to safety, after 68 flights, on the battered staircase that now sits in the museum. "Today, when I think about those stairs, what they represent to me is resiliency," she said.
Also on display were the shoes Florence Jones shed on her way down one of the towers.
"I wanted my nieces and my nephew and every person that asked what happened to see them and, maybe, understand a little bit better what I felt like to be us on that day," she said.
Associated Press writers Josh Lederman, Karen Matthews and Jennifer Peltz contributed to this report.