17 years after the crash, the Flight 93 Memorial nears completion

"This is probably the most challenging and the most unique piece," Murdoch said. "Had we tried it day one, I'm not sure we could have done it."

It became an international project, with wind engineers from Colorado and Australia, a musician from upstate New York, and structural engineers from California and London.

They had to do complicated analyses of wind patterns to make sure the chimes would sound alright, and repeatedly returned to the drawing board while figuring out how they'd swing.

Murdoch said it's all worth it.

"What these 40 people did, I think inspires service in a lot of us," he said. "And I think it's a very important place for Americans to see."

Source: http://www.witf.org/state-house-sound-bite...