The Paralegal: "It was hard to see through the glass. Everything was orange from the burning debris."
Exner proved to be a calm, strong leader that day, but she remembers the scene before her as absolutely "horrific."
"It was hard to see through the glass," she recalled. "Everything was orange from the burning debris."
People were falling from above. There was a lot of blood, she said.
After making her way down the tower and walking several blocks, Exner, then a 21-year-old law student, said she heard the south tower coming down behind her.
She ducked behind the closest building, praying that it would give her some safety from the debris.
Exner, a Brookfield native who is now 31, made it out of the area and walked to her apartment in Chelsea.
That day in September began like any other. Exner was working as a paralegal with Hills Betts & Nash. When she heard a loud "boom" and the building shook, she said she knew she had to get out.
Instead of panicking, her military training took hold, and she started ushering people from the office into the stairwell.
"There were no announcements," she said. "Nobody told us anything.
It wasn't until some of the people from the upper floors with bad burn injuries made their way into the stairwell that she realized the gravity of the situation, she said.
But Exner pushed forward, helping to form a single line so the injured could make their way down to safety and firefighters could make their way up in their efforts to save lives.
At one point, Exner said, she made eye contact with one of the firefighters. He was about her age, and in his eyes she saw fear as he walked up the stairs.
It took years for Exner to learn how to deal with the tragic events of that day. Eventually she realized that she was suffering from post-traumatic stress disorder.
Before she found the right counselor to help her, she suffered from nightmares, depression and a tremendous sense of guilt.
"I felt guilty about surviving when so many others didn't," she admitted.
All of that emotion came flooding out when Exner attended the ceremony in New York City marking the first anniversary of the attacks.
"I just stood there and cried and cried," she said.
Originally on track to become a corporate lawyer, Exner instead turned her attention to juvenile cases and immigration.
"I felt it was important to enter an area of law where I could give something back," she said. "At the end of the day, I can say that I did something positive."
For a short period of time, Exner even served as a volunteer firefighter for a department near her home.
A few years ago, she started Tails of Courage, an organization that rescues dogs and trains them as therapy animals for others suffering from PTSD.
She said the organization is active in several states and has saved more than 350 dogs -- dozens of which were trained as therapy animals for veterans.
"The tragedy taught me a lot about life and doing the best I can every day," she said. "It was important to me that I did something to honor those who didn't make it."
Her mother, Cynthia Exner, said that while her daughter continues to carry the guilt so many survivors feel, she looks at life a lot differently these days.
"She feels a real pull toward doing something to give back to those who helped save her life and the life of so many others," she said.
"I almost hate to say it," Cynthia Exner observed, "but the tragedy was a defining moment in her life that she will remember forever."
Exner continues to credit her daughter's military training for her making it out of the building alive.
"People were screaming and in a panic, but she knew that she had to focus on what had to be done," she said.
"To this day she doesn't talk about it much, but I know she saw some horrible things," Cynthia Exner said. "Nobody knew what was going on, but she stayed in control."