It's what scientists refer to as a flashbulb memory, a moment so powerful the brain takes mental image and keeps it sharp for decades.

For the greatest generation, it was the Depression and D-Day in World War II.

For the silent generation and baby boomers, the JFK assassination.

And for Gen X and millennials, it's the terrorist attacks of September 11th, 2001.

Carolina Impact's Jason Terzis joins us now with the story of a retired New York City firefighter.

- Well, for so many of us, it's simply hard to believe it's been a quarter century since September 11th, not believing our eyes with what we were witnessing unfold on live television and the realization that America was under attack.

343 firefighters died that day, but since then, more than 400 have succumbed to 9/11 related illnesses.

David Forland has dealt with some of those very same illnesses, but he's fortunately still around to talk about it.

- I'm pounding.

- [Jason] It's a Sunday afternoon at the Forland house.

Danielle, Eric, and sons Remy and Jace, playing a game of how many times can we keep this inflatable ball in the air?

Grandpa Dave then inflates an even larger beach ball.

He and wife RuthAnn then join in on the fun.

Retirees, the Forlands moved to Charlotte from New York in 2013.

RuthAnn worked in real estate.

- I did that for 15 years.

- [Jason] Dave in public safety, first with the New York State Police.

- When I was in the state police, I ended up getting transferred down to the World Trade Center.

- [Jason] Where he worked on Governor Mario Cuomo's security detail, but starting a family, Dave jumped from the police force over to fire.

- I just felt like the fire department would be a better choice for my family.

- I actually liked the fact that he was a fireman and I wasn't really afraid of the safety issue of it.

(siren blares) - [Jason] With Dave working at Engine 307, Ladder 154 in Jackson Heights, Queens, RuthAnn would occasionally bring their three young kids to visit dad at work.

- It was just great.

Like at the Christmas party, they'd go to the firehouse and then sometimes maybe we would take a trip in there, if we were going in the city, we'd stop in.

- [Forland] My son, I would take him to the firehouse on occasion.

- [Jason] As a first responder, it wasn't just about fighting fires, it was dealing with just about everything.

- And some nights, we would have over 20 runs on a night tour.

I once had somebody who was delivering a baby on the toilet.

It's not a great call to be on.

- [Jason] But Dave loved the day-to-day of the firehouse, preparing meals together and bonding with the guys.

- [Forland] There's a lot of camaraderie and ribbing.

- [Jason] In early 2001, a side job brought him back to the World Trade Center.

- I was working with my brother-in-law and we were putting up smoke screens down in the subway.

- [Jason] But just a few months later.

- I saw the plane hit and I was like, "What?"

- I was listening to the radio at that point and they said, "Recalling all New York City firemen."

- Then Dave called me, says, "I'm heading back in."

I said, "I know."

I went up and I picked up the kids from school.

- [Jason] With the tragic events of the day unfolding and the Twin Towers ultimately collapsing, Dave and most of his firehouse spent the day on standby at Shea Stadium waiting their turn.

- The people from the kitchens and stuff like that, they started making hamburgers and stuff like that and feeding us.

And I kind of felt like I shouldn't be eating.

There's people underneath the concrete, waiting for us to be down there to help them get out.

But then I thought to myself, I was like, "Are they feeding us because this is our last meal, when we go down there?"

- [Jason] Making it down to ground zero on September 12th, Dave couldn't believe what he was actually seeing.

- It was just so quiet.

That was the thing I remember, it was just like eerily quiet.

- [Jason] He describes being on the pile as nothing but steel and rubble.

- Just searching for whatever we could find whatever we could dig with our hands basically and some tools.

I said to this cop, I said, "We could use some buckets, some five gallon buckets."

And that's when we started with the bucket brigade.

It was like 72 hours before I actually got a break, and that was when the president came down there.

- And the people who knocked these buildings down will hear all of us soon.

(people cheer and applaud) - I mean, he really inspired the firemen.

- [Jason] From there, it was 48 hours on, one day off, repeat over and over.

- I remember feeling like he was never home, and when he did come home, he went to sleep.

- I just took some pictures of what we had encountered.

We didn't feel like we could take any pictures of each other because we were not heroes, the heroes were dead, they were underneath the ground.

- And then after that, it was, the funerals that we had to go to.

And we had a friend from our church who passed away in 9/11 and he was expecting his first baby and his wife gave birth the day of his funeral.

- This is a medal that they gave us for responding on 9/11, but I don't wear any medals on my jacket because I don't feel like I need a medal for doing what I did.

- [Jason] But little did those at ground zero know then is that they were working at what can only be described as a toxic wasteland, the effects of which are still being felt all these years later.

- I remember coming down with rashes pretty much all over my body.

I have issues with breathing, sinuses, all of that.

Asthma, sinusitis, GERD, and then cancers, various cancers.

I've had like 10 operations related to my service, orthopedic operations, prostate, different things.

- And yes, he's had cancer three times and yes, it's been hard, it was a hard thing to walk through.

Shoot.

But you get through it, you just get through it.

Any way you can, you do.

- [Jason] Dave says he feels pretty good overall, and the medical care he receives from the fire department has been excellent.

And despite everything he and so many others went through, he says he would do it all over again.

- I mean, I would never shy away from going back and doing what I did, and I would say all my brothers in the fire service would say the same thing.

Well, this is the fire department patch.

- [Jason] In his home, Dave has tons of pictures and mementos from his nearly three decades with the New York City Fire Department.

- I'm glad that you asked me to do this because it gave me the opportunity to go through and get some of the stuff together that has been tucked away for a while because we don't want the story to die because it was a big sacrifice, many lives.

- [Jason] Today, three of four of Dave and RuthAnn's children are living in the Charlotte area.

The only one not here, son Josh, where after visiting his dad at the firehouse as a kid so many times is now following in his father's footsteps, working in the very same Jackson Heights Queens Fire Department his father once did.

They even gave Josh his dad's old locker.

- I'm very proud, I'm very proud of him.

When he came there and proved himself, then one of the commissars deeded it to him, which is kind of cool.

- I hope that one day he'll be able to hang up his precious photos in there too, you know?

- [Jason] Passing the torch from father to son, one generation to the next, and honoring the sacrifices of those that came before.

25 years is a long time, but will forever remain in the hearts of so many.

- It's hard to hear him talk about it because I remember my son was just a few months old at that time, and when I got to race and pick him up from daycare, from work, it just didn't seem real, but this is a man who lived it firsthand.

I'm so grateful he would share his story with us.

- Yeah, happy to share his story and just as he reiterated a couple times, he doesn't look at himself as a hero, he feels that it's his comrades who died that day, who are the real heroes, even though he's still dealing with some of the effects.

But there's actually a good amount of alumni, New York City Fire Department alumni in the Carolinas.

And David gave me one of these little coins here that they've been passing around.

On the one side, it talks about the, it mentions, you see the picture there, it just talks about the New York City firemen and the 343 guys who died that day.

And on the backside, it's got North and South Carolina.

They do things over at Romare Bearden Park They do a couple things at the... So New York alumni here in the Carolinas all get together for bonding and especially on 9/11.

- Thank you, Jason, for sharing it.

Can't believe it's been 25 years.

- No, nuts.