GEOFF BENNETT: Last night, we brought you the story of the lingering trauma affecting so many Israelis since October 7.

Tonight, we turn to Gaza, where the Health Ministry says nearly 70,000 Palestinians have been killed over the last two years of fighting.

The scale of the death has been staggering and the toll on children overwhelming, tens of thousands killed and thousands left with grievous wounds of war, often treated with near medieval means due to a lack of supplies.

Over the last year, Leila Molana-Allen and our colleagues have followed treatment for some of these children and have this report.

A warning: The story includes graphic images that are disturbing.

LEILA MOLANA-ALLEN: No sight, no speech, no sound; 4-year-old Nayel (ph) has had all his senses stolen by an airstrike, and it's getting worse.

In May, Nayel and his 6-year-old brother were playing in the dusty pathways of Gaza's Nuseirat refugee camp, when an Israeli strike hit the tent next to them.

HANI ABU SHALABI, Father of Injured Child (through translator): They were playing around me when the missiles suddenly hit us and shattered all our dreams and beautiful moments we once had in our life.

LEILA MOLANA-ALLEN: Mohamed was killed instantly.

Pieces of shrapnel lodged deep in Nayel's brain, causing brain damage that's stolen his vision, his hearing and his speech.

With barely any food or access to clean water, Israel has mostly blocked the delivery of eggs since earlier this spring, he's suffering from severe malnutrition.

The filthy conditions in the hospital mean he's now caught meningitis too.

Unable to chew or move, what food they can get him is through a feeding tube.

His tiny body can't hold out much longer.

HANI ABU SHALABI (through translator): Before the war, Nayel was one of the most active children.

He loved to play a lot and we used to go to the beach together.

He's in pain right now, silently in pain, and cries without tears.

The doctors here told us they don't know what to do anymore.

LEILA MOLANA-ALLEN: Nayel's only chance is to be evacuated from Gaza for specialist treatment.

Without it, he will die soon.

He has the travel permit and foreign surgeons desperate to help him.

But the Israeli authorities won't let him cross the border.

Thousands more children have sustained life-changing injuries, which Gaza's hospitals, overwhelmed with the wounded, lacking in basic medical supplies and often under bombardment themselves, simply can't handle.

A lucky few make it across the border into Egypt, but, even there, the most severe cases need specialist help.

Five-year-old Adam (ph) is one of those lucky ones,lucky to be alive, unlucky to have suffered many months of agony and be facing permanent disability because of how long his evacuation was denied.

Displaced three times in the first few weeks of the war, Adam's father and sister were killed when the house they were sheltering in was hit by an Israeli airstrike.

Adam was crushed by the rubble, shattering his arm.

It would have been a fairly simple surgery outside, but with the health care system in Gaza in full collapse, doctors could do little for him.

EID AFANA, Uncle of Injured Child (through translator): I saw many horrific scenes that broke my heart when I entered the hospital, children with limbs amputated.

What did those children do?

LEILA MOLANA-ALLEN: For two months, Adam waited in suffering.

Four times, they requested medical evacuation,each request denied.

EID AFANA (through translator): His arm's condition remained critical.

They did daily cleaning operations on his hand without anesthesia.

His condition was excruciating.

LEILA MOLANA-ALLEN: Finally, the border opened and Adam was taken to Lebanon.

Because of the delay, he'd developed a chronic bone infection.

It was so advanced, he was now suffering from a related brain injury.

Adam's surgeon, Ghassan Abu Sittah, is a British-Palestinian doctor who's campaigned tirelessly to bring injured Gazan children to Beirut's American University Hospital, one of the best in the region.

DR.

GHASSAN ABU SITTAH, Plastic and Reconstructive Surgeon: The worst thing is that the kids that we are treating, we're treating the complications of long-term neglect for these injuries that have not been properly treated.

Let's put it this way.

A friend of mine who's an orthopedic surgeon still left in Northern Gaza tells me that half of the amputations that he's doing could have been saved, those limbs could have been salvaged if they had been treated at the right time.

LEILA MOLANA-ALLEN: Adam has had to endure more than 60 surgeries on his arm to fix the damage from the infections.

It will never be fully functional again.

And with his mother severely injured and the rest of his immediate family dead, his mental scars may be just as debilitating.

EID AFANA (through translator): For the rest of his life, he will continue to relive the horrors he saw.

He's witnessed so much pain and loss.

LEILA MOLANA-ALLEN: The system exists to evacuate and treat these children, but Israel controls who can cross the border to access it.

Barely 100 children have managed to leave in the past 18 months.

Many die while waiting.

A year ago, the world watched in horror as 19-year-old Shaaban Al Dalu burned to death, an I.V.

line still in his arm, when Israel struck the Al-Aqsa Martyrs Hospital compound.

His father, Ahmed, on fire himself, could do nothing to save him, but he managed to drag his other children from the flames.

AHMED SHAABAN AL DALU, Father of Deceased Children (through translator): It was so hard seeing them burning alive.

It tears your heart apart.

It makes your soul ache and breaks you.

LEILA MOLANA-ALLEN: Desperate to save his 10-year-old son, Abud (ph), from the same fate, Ahmed called on the international community to help force his son's emergency evacuation.

But no help came.

Days later, Abud died of his burns too.

AHMED SHAABAN AL DALU (through translator): He was the youngest of my kids and the one I spoiled the most.

LEILA MOLANA-ALLEN: Helpless, the clock is ticking for Nayel and thousands of other children like him.

HANI ABU SHALABI (through translator): We have already lost our first child.

We pray we won't lose our second.

LEILA MOLANA-ALLEN: All they need is for a lifesaving gate to be unlocked.

There's little hope those prayers will be answered.

For the "PBS News Hour," I'm Leila Molana-Allen in Beirut, Lebanon.