National September 11th Memorial officials said Monday they're already working to fix a typo in a victim's name.
Jeffrey Schreier's first name was misspelled on the wall.
A spokesman for the Memorial said two letters were reversed when his named was entered into a database.
In a statement, the spokesman said, "...we are extremely sorry for the pain this mistake has caused Jeffrey's family. As soon as we found out about this error we began working on how to make it right."
Earlier in the day, Mayor Michael Bloomberg and other city officials greeted some of the first visitors to the memorial in Lower Manhattan.
Those who have a ticket will now be able to see the area transformed from a pile of rubble to an eight acre plaza with hundreds of white oak trees and two enormous fountains where the Twin Towers once stood.
Visitors will be able see the names of the 2,977 people killed in the attacks in New York, the Pentagon and Pennsylvania, as well as the six who died during the 1993 World Trade Center bombing.
An accompanying museum is expected to open next year.
"I think today we're going to have 33 countries represented, 46 states, we have to find out those four states that aren't coming today and see if we can get them on, but it is an absolute reflection that this place will bring people together," said 9/11 Memorial and Museum President Joe Daniels.
Many who attended Monday's opening said they experienced a range of emotions during their visit.
"It just brought back a lot of sentimental memories, some intense feelings that I'd sort of haven't thought about for awhile," said one visitor.
"The family members are going to find this a place of peace and healing and I did too I found it a place of healing," said another.
Family members were first to visit the memorial six years in the making during Sunday's tenth anniversary ceremony.
Thousands gathered at the site to hear the reading of names of all those lost.
The ceremony was interrupted by six moments of silence to mark the moments the towers were hit, when they fell, and when the other planes crashed.
Family members walked along the memorial, where the names are inscribed in bronze panels.
They made rubbings of the engraved names, left flowers and gazed at the reflecting pools.
The memorial's designer said watching the response of the victims' loved ones was an emotional experience.
"Seeing this thing that you've built and labored on for so many years, that for so long has been behind construction fences, away from everyone. All of a sudden being embraced by hundreds of family members, and touched and caressed, and literally kissed. It was just an incredibly emotional day," said memorial designer Michael Arad.
Admission to the memorial is by timed ticket only.
For more information, visit 911memorial.org.