October 7 is a day marked in history for the Israeli people. After more than 1200 people were killed in Israel, roughly 240 taken hostage. The country's military response has resulted in thousands more killed in Gaza. And as battles rage on, the events of October 7 continue to resonate with the Israeli people. In tonight's Prime Focus, Ian panel retraces the hours of horror from that day that would ultimately change the community, country and even the world.

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May 2023, the Shivuot Festival in kibutz near Oz. An idyllic place of peace and plenty. An annual celebration of the harvest and a formal welcome to the newest members of this rural community. A time to come together, to give thanks, to play, laugh and sing. A home movie haunting in its happiness.

Neros, before October 7, was paradise. I was born in Neroz. I lived there all my life. My kids loved the place.

He put it. It's like lovely community, that very peaceful, beautiful place like you can see. You feel like you're belonging to someone, to something.

And this is kibutz Niroz today, six months since that Shivuot festival. A community torn asunder, burnt, broken and bleeding. This is the story of what happened on Black Saturday, October the 7th. With unprecedented access to hours of security camera footage, Hamass videos and eyewitness testimony, it's the story of an unspeakable few hours of horror that would change a community, a country and a region forever and unleash. A war that's brought death and destruction to so many thousands a. M. Saturday, the 7 October. Air raid sirens break the early morning calm across Israel. For the residents of Neroz, it seemed another routine alert.

So our morning start at 630 with the alarm jumping from the bed running to the safe room. Then we got the alarm of the information that terrorist in the kibuts.

After an hour or so, there was report in the community group of messages that there are terrorists inside the kibutz. And we started hearing fire, gunshots, and then all hell breaks loose.

Niroz lies less than a mile and a half from Gaza, and within minutes, the militants of Hamas overrun Israeli army border posts and were at the gates to the kibbutz.

They know what they do, they plan it in advance. They know exactly where to go, which house to go.

The kibutz emergency response team tried to fight off the attack bravely, but didn't stand a chance. They were among the first to die. Hamas fighters stormed in from four points and astonishingly, Palestinian reporter Motna Al Najar crossed with the terrorists from Gaza live streaming as the attack unfolded, declaring at one point, I'm inside the settlement, the entire settlement has been seized. His video shows the gunmen moving methodically and ruthlessly through the kibutz, using guns, hammers and drills to break into the homes of terrified residents locked inside, crying alu AKBA, God is great. As they led an hours long bloodthirsty rampage, setting fire to homes, some with families inside burning vehicles as marauding civilians joined the invasion. Plundering and pillaging, hamas came here to kill, destroy, and to take hostages they could use as bargaining chips. The families of the Kibuts have agreed for us to show this video. The first hostage you see is eleven year old Ares Calderon. The reporter urges the gunman to take care of the boy, to keep him unharmed. Shiri Bibas Silverman clutching onto her two sons, four year old Ariel and ten month old Kfir.

That's my house. Terrorists tried to enter to the house, fight with me on the door. Even that it was tight. I was holding it.

Most of the houses in Neroz have safe rooms, but they're not designed to lock from the inside.

I was hoping that nobody will shoot me through the door.

So you're literally hanging on for dear life.

Yeah, like this.

We keep hearing the same story again and again. The attackers trying to force their way into people's homes and people trying to resist this house. You can see all the bullet holes outside as they try to literally shoot their way in. Just come inside, mind the step, and there's broken glass. You can see where the bullets came through. 123-4567 and tragically, you can see the blood where the people who lived here died.

In the house opposite, retired teacher Chaim Perry and his wife Osnat knew they were in trouble. Unable to hold the door closed, Hayem had to make a decision.

It's hard to imagine how much terror there must have been in homes like this. On kibutz, near Oz, an elderly couple hunkered down the terrorists at the door, trying to get in. They held them off once, but they realized they were going to come back. So 80 year old Jaime Perry, to save his 71 year old wife, went out that door to surrender, hoping that the militants wouldn't come back.

Hamas spuriously claims this was a military operation. But their victims at Neroz, like so many places, were all civilians. Not just kibutz residents, but also farm laborers from Thailand and elsewhere. They lived in their own quarters on the edge of the Quebuts, not party to any conflict or dispute, not soldiers, not Israelis, not Jews. But still they were also rounded up, beaten, kidnapped and butchered.

They went from every door, shoot, took them out, and it looked like in the end, they collect all of them together to this home. Put all of them together here.

Yeah. Going.

It'S unbelievable.

Going.

It literally is a bloodbath. So people who come from Thailand to earn a living, try and find a better life, rounded up, put in this room, and slaughtered.

The rampage at kibutz Niroz lasted 6 hours. By the time soldiers from the Israeli border guard arrived, it was too late. The gunmen, the looters, the hostages were long gone. On the morning of October 7, there were 400 men, women and children living in Neroz. By the afternoon, over a quarter of all the residents were gone. 39 people were murdered here. 74 were kidnapped. The largest single group of hostages taken in Israel that day. And for the survivors, for the relatives, there's guilt, fear and unending pain.

Oh, God. Where are you?

Hadas Calderon's mother and niece were killed in the attack.

There is nothing left. It's all dark.

And her two children, 16 year old Saha and twelve year old Erez, seen in the reporter's video, were kidnapped. She counts the days, the hours, unable to properly eat or sleep.

What about my children? Who take care of them now? Who take care of them if they sick, if they heal, if they know and they need medicine? There is a lot of disease now in Aza. It's frightening.

Many Neroz residents were lifelong peace activists. Chaim Perry volunteered with an NGO, bringing sick Palestinians from the Gaza border to hospitals in Israel for treatment.

Ever since he finished being a soldier, he became a strong peace activist, because he said, I've been there and I know what I'm fighting for now. And it's very clear for me, very, very clear, that peace is the only way.

Many believe the Israeli government must share some of the blame and that their strategy in Gaza is the wrong one.

They feel betrayed. And as it's their right to feel this way, I now urge the government, you've betrayed the citizens. First thing, make it right. Release the hostages, do whatever needed. Afterwards, when you finish this, thrive towards a long term solution. That's it. That's the only thing. The way I can see.

And in Elat, where most of the families from Neroz were evacuated to, there's pain in recuperation and terrible sadness, anger.

They took not only life from the dead, they took life from the living. They took away their lives.

Amid all the talk of negotiations to release hostages, the families now wait. In agonizing limbo sometimes hadas calderon talks to her missing children.

If I talk to them now, I tell them that I fight for them, I'm going to bring them home, back soon. They're going to come back, and their father going to come back. And we're all waiting for them and miss them, miss them, miss them so much. I miss their love. I miss to laugh with them. I miss to kiss them, to hug them.

Obviously, your heart is here in the Kibbutz. Your friends, your loved ones, and you've gone through so much. Can Kibbutz Neroz be the same ever again?

Wow.

No, it will never be the same, no doubt. But kibutz Niroz will be again, will be different somehow, I don't know. But definitely Neroz will be here.

The wounds so deep for so many. Our thanks to Ian for that.

Hi, everyone. George Stephanopoulos here. Thanks for checking out the ABC News YouTube channel. If you'd like to get more videos, show highlights and watch live event coverage, click on the right over here to subscribe to our channel. And don't forget to download the ABC News app for breaking news alerts. Thanks for watching.