New York ? An American flag that survived the collapse of the World Trade Center’s twin towers will be displayed during the singing of the national anthem at Sunday’s Super Bowl.

It was the only U.S. flag flying at the World Trade Center on Sept. 11, authorities said, and it continued to fly at the complex even as the twin towers crumbled.

The 12-foot-by-8-foot flag was recovered from the rubble by rescue workers three days later, torn along some of the stripes but otherwise intact. It has become a symbol of patriotism and triumph and the thousands of lives lost that day.

“The first few times I saw it displayed I would actually cry. I would just cry,” said Port Authority Police Sgt. Antonio Scannella, who has escorted the flag to the World Series, the Macy’s Thanksgiving Day parade, the Veteran’s Day parade and a memorial at ground zero. The flag was also displayed at the funerals of the officers killed.

The Port Authority Police Department lost 37 of its officers and 38 civilian employees in what officials say is the largest loss of life by a police department in a single day in U.S. history.

“This flag means a lot,” Officer James Hall, whose partner was killed that day, said Wednesday, soon after escorting the flag to New Orleans. “I knew all of the Port Authority people who didn’t make it. I was scheduled to work that day but they changed my shift to the afternoon.”