This Sunday, Dennis will be hosting an event in New York City called the Tunnel to Towers Walk/Run. The organizer of the charitable event is Frank Siller, one of Dennis' guests on the program today.

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.