This September, to mark the anniversary of 9/11, people from all over the world will congregate in New York City to retrace the footsteps of a fallen hero, Stephen Siller, the brother of today's guest, Frank Siller.

Siller, who raises money for the Stephen Siller FDNY Children's Foundation, explained the significance of the 5K. On 9/11, his brother Stephen, an NYC firefighter, answered the call and ran in full firefighter gear through the Battery Tunnel, from Brooklyn to the World Trade Center, where he perished.

Now, every year, thousands of participants run the same route in this inspired fundraiser in Stephen's honor. For more information on the event, which has been attended by Dennis and Gary Sinise, visit TunneltoTowersRun.org.