Shauna Camp and Anthony Camp, who lost their uncle, Faustino Apostol Jr., in the 9/11 terrorist attacks, look at the panel inscribed with his name during the first day that the 911 memorial plaza was opened to the public at the World Trade Center site in New York, Monday, Sept. 12, 2011. (AP Photo/Mike Segar, Pool) The Associated Press Former U.S. Vice President Dick Cheney, right, listens to 9/11 Memorial President Joe Daniels, center, as he looks at one of the panels inscribed with the names of the attack victims during a visit to the 9/11 memorial plaza in the World Trade Center site in New York Monday, Sept. 12, 2011, on the first day that the memorial was opened to the public. (AP Photo/Mike Segar, Pool) The Associated Press ADDS INFORMATION ABOUT THE PEOPLE IN THE PHOTO - Katina Velahos, right, watches as Zoe Kousoulis makes a rubbing of the name of her daughter Danielle Kousoulis, who was killed in the 9/11 terrorist attacks, from one of the panels inscribed with the victims' names on the first day that the 9/11 memorial plaza was opened to the public at the World Trade Center site in New York, Monday, Sept. 12, 2011. (AP Photo/Mike Segar, Pool) The Associated Press Visitors look over one of the pools at the 9/11 memorial plaza in the World Trade Center site in New York Monday, Sept. 12, 2011, on the first day that the memorial was opened to the public. (AP Photo/Mike Segar, Pool) The Associated Press A woman places her hand on a name etched in the wall of one of the pools at the 9/11 memorial plaza in the World Trade Center site in New York Monday, Sept. 12, 2011, on the first day that the memorial was opened to the public. (AP Photo/Mike Segar, Pool) The Associated Press Visitors looks over one of the pools at the 9/11 memorial plaza in the World Trade Center site in New York Monday, Sept. 12, 2011, on the first day that the memorial was opened to the public. (AP Photo/Mike Segar, Pool) The Associated PressNEW YORK (AP) — Hundreds of thousands of people have signed up for free tickets to see the new memorial at ground zero.About 7,000 people had tickets to visit the memorial as it opened to the public on Monday, and 400,000 have registered online to visit in the coming months, according to the nonprofit organization that oversees the memorial.The monument has two 30-foot-deep pools, bronze plates with victims' names and grove of 200 oak trees.Many visitors made pencil-and-paper rubbings of the names to take back home. Others left flowers or written messages.