AMNA NAWAZ: Recently, the small Israeli town of Nir Oz, which was devastated by the October 7 terrorist attacks, held a unique concert.

The singer was not a musician, but a former American-Israeli prisoner who was kidnapped by Hamas on October 7 and held in Gaza for nearly 500 days.

Producer Karl Bostic in Israel and Nick Schifrin report on his story of survival.

NICK SCHIFRIN: In this sun-drenched corner of the country, just two miles from Gaza, they came from all over Israel, 3,000 concertgoers waiting for a story of strength in a place that's still fragile.

A proud father explains.

JONATHAN DEKEL-CHEN, Father of Sagui Dekel-Chen: He's bringing us together here in a way to be -- to have some kind of closure and for him healing, and I think collectively healing as well.

NICK SCHIFRIN: He is Sagui Dekel-Chen.

He's not a professional musician nor singer, but a hometown hero, a father, and a survivor who didn't know whether he or his family would live to share their story.

SAGUI DEKEL-CHEN, Israeli Hostage Survivor: My goal was for people to have a different form of understanding of what happened in Nir Oz and what captivity is.

NICK SCHIFRIN: On October the 7th, 2023, Dekel-Chen was kidnapped from Nir Oz and taken to Gaza after he was shot protecting his family.

A tide of terror had rolled into the kibbutz.

No Israeli community paid a heavier price.

Of 400 residents, more than 40 were killed, another 70 taken hostage.

And the last thing that Dekel-Chen heard, gunmen storming his house with his seven-month-pregnant wife and daughters hiding inside their safe room.

SAGUI DEKEL-CHEN: I heard gunshots, explosions, terrorists screaming inside my house.

So, for me, what are all these noises?

It's game over, right?

So, as far as I knew, I don't have any family to go back to.

But I understood very soon that I'm going to need to lie to myself, because if that's what I'm going to think or believe, I won't survive.

NICK SCHIFRIN: His descent into hell into Gaza's tunnels lasted 498 days.

The conditions were unspeakable.

And that lie often wavered.

SAGUI DEKEL-CHEN: I always had the date of when my wife is supposed to give birth.

But as far as I know, she's - - she's not giving birth to anyone, she's dead.

And I always knew the birthdays of my girls, but my girls are dead.

But I held very strongly this internal lie.

Sometimes, I couldn't hold it anymore, and the lie broke, and then I would just cross into very deep depression, but then the lie would come back to me and I'm alive again.

NICK SCHIFRIN: And that lie in those tunnels forged the crucible of his survival, for, when everything is taken, the last of human freedoms is to choose one's own way.

SAGUI DEKEL-CHEN: The only choice you have is what you're going to have inside yourself, because everything outside your body is not your choice, nothing.

Why not make up songs?

It took me -- it took me a lot of time, and I'm happy it took me a lot of time, because this is what kept me alive.

NICK SCHIFRIN: Kept him alive long enough so he could be part of a prisoner swap.

In February 2025, Hamas paraded him in front of a global TV audience.

He was finally free.

And as he recovered in the hospital, he recorded on his phones the songs he'd composed in captivity, all from memory, without pencil or paper.

(SINGING) NICK SCHIFRIN: Songs of survival and hope.

He imagined they were lullabies for his daughters.

SAGUI DEKEL-CHEN: All these, like, imaginary bedtime routines, it was part of the lie, but I had no choice but to tell to myself that someone's waiting for me.

NICK SCHIFRIN: It turns out they were waiting.

His wife had survived, his mother, his father, Jonathan, and his children, including the daughter that he wasn't sure had even been born.

In captivity, he wrote this song for her: "I still don't know your name."

He knows now.

Shahar, who will soon turn 3, survived to see her father's concert.

So did 5-year-old Gali and 9-year-old Bar, the oldest daughter, with her grandfather, Jonathan.

JONATHAN DEKEL-CHEN: Bar is an incredibly brave girl.

And she survived with her younger sister and her seven-month pregnant mom the massacre on Nir Oz.

And she was also incredibly brave for the nearly 500 days that her dad was in captivity, and none of us knew what the end of that story was going to be.

NICK SCHIFRIN: In some ways, the concert was the culmination of that story, a sharing of his joy, his grief, with thousands of friends and family on a grass lawn that charts the history of Nir Oz and Dekel-Chen himself.

SAGUI DEKEL-CHEN: So I decided doing a concert, and I decided doing it in Nir Oz because this is the only place where it's true.

This grass lawn, I grew up on it.

It's where I had the first date with my wife, Mili.

Later on, I grew up my girls there in that grass lawn.

Later on, I was fighting on that grass lawn.

If there is a line of this is someone who's totally broken, and this is someone who is alive, I think this event was the first time we crossed the line for Nir Oz.

NICK SCHIFRIN: Crossed the line not only for Nir Oz, but also his family.

SAGUI DEKEL-CHEN: The first time my girls agreed to go back to the kibbutz was the day before the concert.

For them, the kibbutz - - there is no kibbutz.

The kibbutz is a bomb shelter with darkness for 10 hours.

This is the only thing they remembered.

And the moment they got off the car into this grass lawn, they were free.

They felt free.

They were running around.

They were feeling like this is their place, this is their home.

NICK SCHIFRIN: His daughter's cards now fill his front door, because, for Dekel-Chen, the true act of triumph was to be able to be a father once more.

For the "PBS News Hour," I'm Nick Schifrin.