The philosopher George Santayana had it right.

Those who cannot remember the past are condemned to repeat it.

Yet history repeats itself if we remember it or not.

Sneak attacks unite us.

Pearl Harbor and 9/11.

Some wars divide us.

Yet thousands of Americans, even those trapped behind Taliban lines in Afghanistan, remember what happened on a cool, clear September 2001 morning.

Misguided young Muslims hijacked and committed suicide flying 4 US airliners.

They took with them almost 3,000 Americans at the World Trade Center, the Pentagon and in a field in western Pennsylvania.

“We must never forget,” says veteran Dan Hennigan of Lexington. He and his volunteers have worked to make sure we do not forget.

In Columbia Friday evening, many firefighters, law enforcement officers, emergency medical technicians, current and retired military veterans joined other volunteers in the Tunnel to Towers Run and Walk. They joined together to raise money to build and renovate homes for wounded warriors and their families.

They partner with the Tunnel to Towers Foundation that Charity Navigator has given a 4-star, 100% rating on accountability and transparency.

Among the runners were Richard Wright, a retired NYC police officer and US Air Force veteran now living in retirement in Lexington.

He was joined by National Guard Sgt. David Barrows and his wife Katherine, an EMT and military veteran.

Retired US Marine veteran David Pelley of Lexington was joined by his Marine brothers from as far away as California who had not seen each other since 1995.

They ran 5 kilometers from the Convention Center to the Gervais Street bridge, through West Columbia and Cayce, across the Blossom Street bridge and back to the starting line.

They were honoring the courage, example and memory of Stephen Siller, a Brooklyn, NY, firefighter.

Heading for a game of golf, Siller heard on his scanner about the tragedy at the North Tower.

He donned his bunker gear and ran through the closed Brooklyn-Battey Tunnel to the twin towers of the World Trade Center.

There, like more than 400 other 1st responders, he gave his life to save others.

His brother Frank formed the T2T foundation in his honor to raise millions of dollars for wounded warriors, 1st responders and their families.

Like him, Dan Hennigan founded the 9/11 Remembrance Foundation of SC to honor those who serve and raise money to help them.

“Our military members and 1st responders are our heroes,” Hennigan said.

“We must never forget them - nor 9/11.”