At 9:37 a.m., Sept. 11, 2001, American Airlines Flight 77 crashed into the Pentagon after being hijacked by terrorists. Inside the building, 125 service members and civilians were killed, as were the 59 passengers on the plane. Many others were injured. 
Among about 20,000 people in the Pentagon that day were Kathleen H. Hicks and Christopher W. Grady. 
Hicks, now deputy secretary of defense, and Grady, now a Navy admiral and vice chairman of the joint chiefs of staff, spoke about the attack at the annual 9/11 Pentagon Employee Observance Ceremony in the Pentagon. 
"Those of us who were here bear a special responsibility to tell our stories," said Hicks, who told her own story at last year's 9/11 commemoration. "Everyone who was in the building that day has a unique story to tell," she said. 
Mark Lewis helped wedge open a pair of double doors so people could get out of Corridor 4 and into the A Ring. Natalie Ogletree stayed with a badly burned coworker and comforted that person until a medical evacuation team arrived, and John Baxter led a medical team into the fire to search for wounded colleagues and treated patients in the Pentagon courtyard before moving to the triage location outside the building. 
"All of us have a story," Hicks said. "It would take hours to tell them all, so we don't. And yet, we cannot let these stories, our history be lost to time."
As more people progress in their careers and their lives, there will be fewer people working at the Pentagon who were there on 9/11, she said, encouraging employees to seek out those who were present. 
"Take the time to listen, really listen to what they have to say," Hicks said. "If they lost a colleague, don't just ask how they died; ask how they lived — and don't stop there. Help us share these stories for future generations. Because as we tell individual stories of 9/11, we also tell the story of the Pentagon itself, of this building in this community — a story of resiliency and renewal, of a reconstruction project born out of ashes, determined to rebuild stronger."
Grady spoke about those who were inspired to serve following the attacks.
"We give thanks for a generation inspired to step forward to serve their country and to defend it," he said, calling attention to the over 800,000 service members who fought to dismantle terrorist networks that would seek to do us harm. 
"May the knowledge of our shared history ensure future generations of Americans enjoy the same freedoms and liberties that we have had inherited," Grady said. "May we continue to tell the stories of that fateful day 21 years ago and of the days that followed, where we as a nation united in purpose and common cause remain ready to protect and defend our nation and all that it stands for."