COLORADO SPRINGS, COLO. -- The anniversary may be over, but members of the 21st Space Wing spent Monday paying tribute to the men and women who gave their lives during the Sept. 11, 2001 terrorist attack.

An unveiling ceremony took place Monday morning at the Cheyenne Mountain Air Force Station.

The ceremony was used to reveal an artifact donated by the National Homeland Defense Foundation and a display by students of the University of Colorado - Colorado Springs (UCCS) and members of the 721st Civil Engineer Division.

Students revealed a steel beam that was part of the Twin Towers in New York City prior to the attack in 2001. 

Four engineering students had been designing and constructing the memorial for about 15 months and received the beam in November.

"To actually see it there, and to actually see the beam again, but now configured for a purpose instead of on the back of a truck, it's hard to put into words," UCCS Associate Engineering Professor Peter Gorder said. 

Station Installation Commander Col. Joseph Turk said the memorial helps unite the community.

"It's a lasting reminder of that day, the impact that it had to this community, to the military families that live in this community, and as a remembrance of that day and the sacrifices that are made today to defend our freedom," Turk said. "What a tremendous honor to be part of that."

Though the memorial at the Air Force station isn't open to the public, people can visit another one on the UCCS campus. The beams from the towers at each memorial point toward each other across the city of Colorado Springs.