Retired four-star Army General Jack Keane reflected on what he will never forget about the 9/11 terror attacks when he was at the Pentagon on "Fox & Friends."

The Fox News senior strategic analyst was in his office when the South Tower of the World Trade Center was hit, and the "born and raised New Yorker" instantly knew it was a terror attack even before the Pentagon was attacked and smoke was filling his office.

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"It was a horrific day," he said, recalling a visit to the wounded in the hospital that night, seeing the resolve and pain on their faces.

"But the next morning, I will never forget the next morning," Keane said.

He recalled Pentagon employees, most of whom were civilians, came to work the next morning "shaken," but with resolve, he said.

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"They knew we were at war," he said. "They knew they were involved in something much larger than themselves, much larger than their own fear. Yet, here they were standing there, willing to make that kind of contribution. Never will forget it."

The Pentagon held an awards ceremony a few weeks later that moved Keane.

"There were men and women there. There were soldiers and civilians. They were young. They were old. They represented people who were Black, Brown, White, there were different religions there," he said.

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"But it reminded me of somethin-- that courage, raw, physical courage where you're willing to give up your life for somebody else that doesn't have a race, it doesn't have a religion, it doesn't have a size. It doesn't have a shape," Keane said. "What it is all about is heart and character.

"When you're willing to submit your life to save another and that is true honor, and that is the most unusual and unique and largest award ceremony I have ever participated in my life," he said, "and I was so proud to be among them just as we've been talking about the first responders and the heroes at the World Trade Center on 9/11 and what took place in Shanksville in Pennsylvania with those marvelous heroes on that airplane."