The enormous National 9/11 Flag has been unfurled at the World Trade Center site in a ceremony to mark the public opening of the National September 11 Memorial Museum.  

 

After the flag was refolded, firefighters marched it into the museum.  

 

The flag was flying from a building near the World Trade Center on Sept. 11, 2001. It was later found shredded in the debris of ground zero.  

 

People touched by other disasters and tragedies helped piece the flag back together.  

 

Organizers say it now includes three threads from the original Star Spangled Banner. It also has a piece of the flag Abraham Lincoln was placed on after he was shot.