NEW YORK — At 8:32 a.m. Wednesday morning, on the first day that the National September 11 Memorial Museum opened to the public, 26 uniformed police officers and firefighters marched onto the lawn of the memorial and unfurled an American flag that had flown at 90 West Street, adjacent to Ground Zero, for weeks after the attacks. Civilians involved in the restoration of the flag and children from the 9/12 Generation Project filled in among the honor guard designated to see the National 9/11 Flag safely back to Ground Zero. Grasping the edges, they raised the 36-foot by 26-foot flag as the Fire Department of New York’s Emerald Society Pipes and Drums Band played. “Kids, kids, today is a very important day. We’re here to remember, pay tribute, and learn about what happened on 9/11. But we’re also here to remember, pay tribute, and to learn about what happened on 9/12,” said Jeff Parness, founder and chairman of New York Says Thank You Foundation. “People from all around the world came here to help us in our time of need.” Torn and damaged by smoke and debris, the flag was removed in October 2001, and for the next seven years it lay in storage in Pennsylvania. Over the course of two years, more than 30,000 people in all 50 states, all of whom are survivors of tragedies in the United States, from Pearl Harbor to Columbine to Joplin, have helped repair the flag, Parness said. “The 9/11 flag is living proof that love is stronger than hate,” Parness said. The civilians dropped away; the honor guard folded the patched flag; and the Emerald Society Pipes and Drums Band marched from the lawn of the South Tower toward the museum entrance, where the first tour group waited in line. At 8:56 a.m. members of the public entered.