In the ten years since al-Qaeda attacked the United States on September 11th, 2001, the terrorist group has grown, morphing into several offshoots that have been responsible for a series of attacks against the U.S.

FOX National Security Correspondent Catherine Herridge reports in Part 28 of our month-long special series, "9/11: 10 Years Later":

In our next report, Afghanistan through the eyes of U.S. soldiers still fighting there to tame the terrorist threat.

CLICK HERE to listen to Parts 1-27 of our month-long special series, "9/11: 10 Years Later"