AZUSA, Calif. (KABC) -- Retired New York City firefighter, Clarence Singleton is sharing his survival story about what happened to him on Sept. 11, 2001 to a group of students at Sierra High School in Azusa.
South Tower when a group of terrorists deliberately crashed two airplanes into the Twin Towers of the World Trade Center.
He's in Azusa to mark the 21st anniversary of 9/11 and to teach students about what happened on that day.
They weren't born when it happened, but they're getting a survivor's viewpoint of what happened in one of the darkest days in American history.
Singleton said he loves going to schools to teach young students about what happened so the memory of loved ones can be kept alive.
"I believe that we don't truly die until we stop being remembered," Singleton said.
Singleton has spent much of his adult life in public service and received a Purple Heart for his service.
As a U.S. Marine, he was seriously wounded in Vietnam. After that, he joined the New York City Fire Department and retired in 2000. He volunteered on 9/11 to help get people out of the Twin Towers.
He was seriously injured that day.
He and other 9/11 first responders travel the country to share their experiences as living reminders of that fateful day 21 years ago.
Student Isaiah Juarez said it was interesting to listen to Singleton.
"Having someone that's there is really something I loved to learn about. Having someone as a first person perspective is really nice to get information on," Juarez said.
After each visit, Singleton presents a Freedom Flag Foundation banner. It symbolizes where the attacks took place, those who died and those who went in to save lives.
It's a reminder of what was lost that day, but also our resolve to move forward as a country -united.