The 9/11 survivor story that stays with me: David Muir reflects

Of the last 25 people who made it out of the World Trade Center's south tower on Sept. 11, 2001, Florence Jones was number 18.

Her story is one I have always carried with me.

Sept. 11, 2001, was a beautiful morning, until it wasn’t. Like so many, Florence has long described the clear, blue skies, and the kindness on full display. That morning was like so many others, until she says, it descended into hell on Earth.

Florence worked as a manager on the 77th floor of the south tower. The north tower was hit first, and she remembers going up to 78th floor to tell colleagues they should leave. She went back down the escalator to the 77th floor and moments later, the second plane hit. Just one floor above her.

Many of the colleagues she had just seen were now gone, including Jill Maurer Campbell, a young mother. Florence has always said she will never forget Jill’s smile, especially the day Jill brought her baby boy, Jake, to the office.

When the second plane hit, Florence had to find her own way to escape. She joined a small group of colleagues and started down the smoke-filled stairwell, holding hands, holding each other’s shirts, guiding one another. She remembers her boss, fearing Florence might fall on the way down, suggesting she take her shoes off. He carried her shoes the rest of the way down. They helped each other out.

For years, those debris-covered shoes sat in a box under her bed. Now, they’re in the 9/11 museum.

Florence survived the attack on the twin towers and ever since, has always conveyed a quiet sense of purpose, a sense of responsibility after having survived that dark day.

She has shared so many deeply personal reflections. For one, she will never forget looking out and seeing men and women in the north tower standing at the window’s edge after the first plane hit.

“To see these young people doing the sign of the cross and jumping. You’re like, oh my God,” she told me.

It remains one of her most painful memories of that day. Florence has always said she didn’t look away out of sheer dignity for those who had no choice. She believed someone needed to bear witness to their suffering. To this day, she says they were among the true heroes of that day.

Ten years ago, she took me along on what used to her walk to work, past the fire station where she would always wave to the firefighters standing in the doorway. Florence had not been inside Ground Zero until she went with us then. The giant craters left from the towers were now reflecting pools.

As we approached the pools, Florence put her hand to her face. And we knew. It all came flooding back. The loved ones, the colleagues, and the faces of those brave men and women who never made it out.

Etched in bronze at the pool’s edge, among the thousands of names, was her friend's -- Jill Maurer Campbell.

Recently, 20 years after 9/11, Florence received a phone call from Jill's son.

Jake Campbell, who is now nearly 20 years old, asked her if she could offer anything she remembered about his mom.

Florence told him of her smile, her kindness, and her one true joy: being a mother. She told Jake she remembers that she had never seen his mother happier then that day she brought him to the office all those years ago.

Then, having learned of Jake's own life -- he's now a student at the University of Michigan -- Florence told him that his mother would have been very proud of him.

On this 20th anniversary of 9/11, I had the chance to meet Jake. He told me those words from Florence were a gift.

Watch a special edition of “20/20” with David Muir on Friday, Sept. 10, at 9 p.m. ET on ABC.