Tens of thousands participated in New York City's Tunnel to Towers 5K on Sunday, September 29th, a poignant tribute to the lives lost in the September 11, 2001 attacks. The event retraced the courageous journey of firefighter Stephen Siller, who ran through the Brooklyn Battery Tunnel to reach the Twin Towers. Participants were greeted with clear skies and sunshine, a welcome change after an initially damp morning.