GEOFF BENNETT: Amnesty International is accusing Israel of committing genocide in Gaza and is calling on the U.S. to block weapons transfers.

In response, Israel's Foreign Ministry called the nonprofit deplorable and fanatical and said its report was entirely false and based on lies.

For the last two months, Israel has been waging a new operation in North Gaza.

Nick Schifrin has the story of one Palestinian man whose family says he was caught in the crossfire.

NICK SCHIFRIN: In North Gaza, Mahmoud Almadhoun fed the famished.

They called him Chef Mahmoud for running a soup kitchen for the most vulnerable.

His team filmed these scenes for us back in March, providing sustenance to stop starvation.

He told us he had to help.

MAHMOUD ALMADHOUN, Soup Kitchen Organizer (through translator): When you think you're going to die, you want to start serving and helping others.

It's like a new lease on life.

NICK SCHIFRIN: More recently, he opened a school with a sign on the roof in Hebrew and English, "Please don't bomb."

And that's him in red wheeling in water and providing much-needed produce to the besieged Kamal Adwan Hospital.

MAHMOUD ALMADHOUN (through translator): We hope for more vegetables for the sick and the injured and the children and medical staff.

NICK SCHIFRIN: That was his last public statement.

Four days later, on the morning of November 30, Almadhoun's family says he was killed by an Israeli drone, his 15-year-old son, Omar, seriously injured beside him.

A few weeks before, his family says the school he'd opened was also attacked.

For two months, the Israeli military has waged a new operation in Northern Gaza, targeting what it describes as members of Hamas, some of whom participated in the October 7 attacks.

Israel has uncovered weapons stockpiles, including bombs, as seen in this captured Hamas video, in what Israel calls a Hamas rocket launch site.

LT. COL. YOEL, Israeli Defense Forces (through translator): We will reach any location where the enemy places launch facilities or anything that fires towards the citizens of the state of Israel.

NICK SCHIFRIN: Israel also says, at Kamal Adwan Hospital, it's facilitated the evacuation of patients and the delivery of fuel, medical supplies and food and water.

It accuses Hamas of stealing aid.

But U.S. officials say, as Israel has tried to evacuate the entire area, it's not allowed in nearly enough aid.

So, Almadhoun was trying to provide what he could.

He leaves behind his wife, Alaa, and seven children, the youngest, Aline, barely 2 weeks old.

FATIMA ALMADHOUN, Mother of Mahmoud Almadhoun (through translator): At Kamal Adwan Hospital, day after day, he brought food, gave money to those in need, the young, the old.

This is a great honor that Mahmoud was martyred as he fed the people.

I hold my head high for him.

NICK SCHIFRIN: When I spoke with Mahmoud Almadhoun earlier this year, I also spoke to his brother, Hani Almadhoun, who joins me now.

He is also the director of philanthropy at UNRWA's independent American arm.

Hani Almadhoun, thank you very much.

Thanks for being here.

Let's talk about your brother.

Tell me about him.

Tell me about the work he was trying to do.

HANI ALMADHOUN, Director of Philanthropy, UNRWA USA: My brother Mahmoud is a great guy.

He's my baby brother.

He started a soup kitchen.

When we couldn't figure out how to feed our family, our neighbors, he started cooking, like, for -- a dinner or lunch for people that we knew all our lives.

And he cooked.

First day, 120 families ate, and then he thought, this is it.

But then kids showed up to the house asking for food.

And he said, hey, let me figure this one out.

So he's a business guy.

He would go.

And, like, if he finds potatoes, he would buy whatever the dealer had.

And at the time, there was no pasta or rice or any starchy things, so potatoes was a big deal.

He bought it and cooked for the family, for the neighborhood, started serving up to 600 families every day.

And it's just beautiful, because I worked for UNRWA USA, and we couldn't because Israel banned UNRWA from working in North Gaza early on.

We pivoted to do small shop, soup kitchen, like the Gaza soup kitchen.

And, unfortunately, things did not turn the way that should turn.

NICK SCHIFRIN: We heard from him a little bit in the story we just played about why, what motivated him.

What do you think motivated him to do what he did?

HANI ALMADHOUN: He just saw a problem, and he wanted to solve, because we knew we have the means.

I live in the U.S. And people were sending money in my private bank account Zelle, hey, go figure out how to get food to people.

And it was hard.

There's no banks.

There is no phones that were working at the time.

But then he figured out a way to do it, leaning on the local farmers, leaning on the nature.

When it rained, he had a lot of leafy greens that he could find and just chop and cook up.

Literally, he would go, and 7:00 a.m., my mom would wash the veggies and cook.

But then eventually he hired a lot of people that -- because we wanted to scale.

And we expanded beyond Beit Lahia, where we started.

And, unfortunately, things -- instead of celebrating my brother's achievement and enjoying a possible cease-fire, now we have to mourn his life.

NICK SCHIFRIN: Tell me about how he died.

HANI ALMADHOUN: On Saturday around 9:00 a.m. local time, he left the third or fourth shelter he's based at.

He walked about 30 yards or less outside the house and a drone was waiting in the neighborhood and just shot at his feet, and an explosion was -- led to his death.

Basically, he died on the spot.

Our friends who saw him tried to rescue him.

They thought they could save his life, tried to take him to Kamal Adwan Hospital, where he was headed.

NICK SCHIFRIN: The very place that he was trying to help.

HANI ALMADHOUN: He was -- wanted to make sure they got the produce, because the day or two days before, he ordered the large shipment to produce.

That's largely restricted in North Gaza.

And they couldn't because there was sniper fire.

And you don't really believe it, because this is -- this has turned into a legend.

This guy is always there with videos and solving problems.

And people really lean on him to provide those meals.

And, sadly, we buried him.

And he leaves behind the legacy that's respected across the globe, people who mourn him who live in the U.S. and people who live in Palestine, but also seven kids.

NICK SCHIFRIN: I reached out to the Israel Defense Forces, and they said they were formulating a response on your brother's death, but have not, as at this moment, provided me any response.

And as I mentioned in my story, what the context is, there's been an operation in Northern Gaza that the Israelis have launched for the last couple months, Jabalia, Beit Hanoun, around the Kamal Adwan Hospital, where your brother was helping.

The fighting's been fierce.

Israel says that it is targeting Hamas fighters, targeting Hamas ammunition, infrastructure.

But as I also pointed out, U.S. officials say that Israel has not allowed enough aid into Northern Gaza.

How short of basic necessities, as far as you can tell, are the people living in North Gaza?

HANI ALMADHOUN: It is real.

We feel it, because the famine, it brings people to our soup kitchens.

More families have to be fed, and we work together to provide those meals.

Now, eventually, what's in Gaza is, there's really not much food left.

There is probably canned meat.

There is some lentils.

That's what's feeding the north right now, some flour.

However, in the south, they're running into crisis with flour, where one bag of flour, that's about a 50-pound bag of flour, will bring about $1,000.

That's a lot.

And you could buy the same bag here for $15.

NICK SCHIFRIN: And the problem with the black market, Israeli and U.S. officials admit, is that criminality has skyrocketed, especially where you just mentioned, Southern Gaza, Central Gaza.

There's not a lot of security at all, and that has led some other organizations to stop even delivering aid at all.

HANI ALMADHOUN: Right.

NICK SCHIFRIN: In terms of your family, will you guys try and continue your brother's legacy?

HANI ALMADHOUN: My brother always finished his videos with saying two things: "I send my love to all my friends in the United States," and he would say in Arabic (SPEAKING IN FOREIGN LANGUAGE) "We will continue."

And we are trying to do this.

We expanded our operation in different parts of North Gaza.

That means we have now three active full soup kitchens in North Gaza and two in the south.

I look forward to the day we're not expanding because the need is gone.

And you have mentioned the criminality.

I do want to -- people think it's complex.

Wrong.

This is -- these are organized criminals that somehow the Israeli army is turning a blind eye to.

This is not somebody who's -- it's not rocket science.

These people carry guns within 10 meters away or 20 meters away from the Israeli army.

If they wanted to stop these criminals, they can.

But they choose to look the other way, creating that massive need we see in both North and South Gaza.

I pray we're close to a cease-fire, but it's sad because I'm not going to celebrate the cease-fire with my brother Mahmoud, who was my partner during these difficult times.

NICK SCHIFRIN: Hani Almadhoun, thank you very much.

HANI ALMADHOUN: Thank you very much.