Tunnel to Towers CEO Frank Siller and Sen. Joni Ernst, R-Iowa, joined forces Sunday to honor the strength and sacrifice of 9/11 heroes, participating in the 104-story Freedom Tower climb after a two-year hiatus.

The duo appeared on "Fox & Friends Weekend" along with a group of event participants after completing the climb to share its significance and explain what the process entails.

"It's important that we always remember the sacrifice that was made just over 20 years ago," Siller told host Pete Hegseth. He recognized the young professionals standing behind him, noting their contributions to the organization and their purpose for participating – to honor the life and sacrifice of Lt. Joseph Leavey, a firefighter who died during rescue efforts at the World Trade Center on September 11, 2001.

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This April 21, 2015, file photo, shows the top floors of New York's One World Trade Center in Lower Manhattan. The observatory atop the 104-story skyscraper is scheduled to open to the public on May 29. (AP Photo/Mark Lennihan, File)

This April 21, 2015, file photo, shows the top floors of New York's One World Trade Center in Lower Manhattan. The observatory atop the 104-story skyscraper is scheduled to open to the public on May 29.  (AP Photo/Mark Lennihan, File) (The Associated Press)

Erica Oelkers, the starter for this year's event, lost her husband to a 9/11-related illness last year, another tragic example of the attack's lasting consequences.

Ernst, a U.S. Army combat veteran, also participated in the event, offering a shout-out to Gold Star family members in attendance and calling attention to U.S. service members lost in the War on Terror.

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"It's a way to remember and to do good as well," she said.

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Siller said the climb takes anywhere from approximately 15 to 45 minutes depending on each participant's pace and delved into Tunnel to Towers' ultimate goal to end homelessness afflicting many of America's veterans. Siller also circled back to the purpose of remembering the heroes of 9/11 throughout the segment, presenting a list of first responders participants sought to honor with their efforts.

"This is what this event is all about. To never forget and to honor them," he said.

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