Nearly 40,000 people are expected to participate in the event, which retraces the final footsteps of FDNY Firefighter Stephen Siller on Sept. 11, 2001, from Brooklyn to Lower Manhattan.
Assigned to FDNY's First Squad, Siller had just finished his shift and was on his way to play golf with his brothers when he heard over the radio that a plane hit the north tower of the World Trade Center.
In response, he drove his truck to the entrance of the Hugh L. Carey Tunnel, formerly known as the Brooklyn-Battery Tunnel, but found out it had closed. Siller then strapped 60 pounds of gear to his back and raced on foot to the Twin Towers, where he sacrificed his life to save others in the terror attack.
This year, Tunnel to Towers is also honoring another first responder killed in the line of duty: NYPD Officer Jonathan Diller.
ALSO READ: Thousands remember fallen NYPD Officer Jonathan Diller
Thousands remember fallen NYPD Officer Jonathan Diller at funeral service on Long Island
The NYPD officer was fatally shot while responding to a traffic stop in Far Rockaway, Queens this past March. Diller, who was posthumously promoted to Detective First Grade, left behind his wife and one-year-old son.
Following Diller's death, Tunnel to Towers announced that it would pay off the mortgage on Diller's Massapequa Park home.
Part of Tunnel to Towers' mission is to support families of fallen first responders in the long run, including Michele Brooks, widow of Newark Firefighter Captain Wayne Brooks.
She says she got a call from the foundation's CEO, Frank Siller, following her husband's death.
"Blink and now you're alone, and you know that security left with my husband," Brooks said. "When this all happened I got a phone call from Frank, and when he said they would pay off the mortgage, that was just another piece that I didn't have to worry about anymore. And with my husband being gone, that really brought me a little bit of peace."
ALSO READ: Injured New Jersey trooper moves back home after special renovation by Tunnel to Towers Foundation
Tunnel to Towers foundation unveils smart home renovations for injured NJ trooper
Charlotte Scherr, widow of U.S. Army Veteran David Spadell, also spoke about the significance of the organization and its cause to her family.
"They've taken care of our travel, taken care of our stay. Being able to be a part of something that represents way more than I can even fathom, and to be able to teach the boys about more than what they can even understand as to why this exists has been absolutely amazing," Scherr said.
The Tunnel to Towers 5K Run and Walk began in 2002 with 1,500 people, and is considered to be one of the top 5K runs across the U.S.
You can learn more about the event and the organization's mission on the Tunnel to Towers Foundation website.
ALSO READ: Brides left scrambling after NJ event space files for bankruptcy
Popular wedding venue foreclosure leaves hundreds of couples in NJ without location
----------
* Get Eyewitness News Delivered
* More Manhattan news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube