The North Tower of the World Trade Center collapses on Sept. 11, 2001 Det. Greg Semendinger/NYPD/AP hide caption
Sen. Tom Coburn, R-OK. Win McNamee/Getty Images hide caption
Firefighters make their way through the rubble of the World Trade Center in New York on Sept. 11, 2001. Doug Kanter/AFP/Getty Images hide caption
The World Trade Center towers, on 9/11/2001. Robert Giroux/Getty Images North America hide caption
