"It brings into reality that you don't know what could happen every single day. And that we're lucky to be here," said Isabella Zon, a senior.
"Each and every one of these people had their own story to tell and their own lives. And it's just a tragedy that that happened. And by having each flag represent each person it's nice to remember them," said Maximus Rodriguez, a senior.
"Everyone one of these flags is not a material. It's not a piece of property. It's a person," said Steve Gallagher, a history teacher.
This especially hits home for Stefania, who lost her aunt on 9/11. She placed one of her flags by her aunt's name.
"Even though I didn't know her personally my dad would always tell me about how she was a really outgoing and creative person, and even though I didn't know her I still miss her," said Stefania Izzo, a sophomore.
These students weren't born yet when tragedy struck, but their history teacher, Steve Gallagher, a New Jersey officer that worked the grounds of 9/11, says it's important for his students to understand how much this hit close to home
"I think for them to take away that the people next door to them, and how fragile life is. And that when you left the house this morning to say goodbye to your parents there's no guarantee that you're coming home or they're coming home. And I think that's something that they dwell on. When they put a flag down and see that kids their age lost their parent," Gallagher said.
The memories of that day are painful, but these kids realize that honoring the lives lost and the heroism of first responders brings us together as a country.
"I think when there's so much division in our country bringing something that everyone knows about that everyone can be on the same page about. I think it's something that everybody can just do together and it's something that brings us together. And, reminds us that we are here and it's a country that's here for all of us. And it's a great one to be in," Zon said
In addition to placing the flags, the students also learn more about September 11 in an assembly presented by their teachers.
CLICK HERE for more Eyewitness News reflections, photos and stories marking the anniversary of 9/11
'Eyewitness to 9/11: Behind the Lens' reveals untold stories, rare video of America's darkest day
How reporter N.J. Burkett and his photographer escaped Twin Towers collapse
In memory of Don DiFranco, WABC engineer killed on 9/11