AMNA NAWAZ: Welcome to the "NewsHour."

Gaza's health care system and its central hospital are in collapse more than five weeks since the Hamas terror attacks that sparked this war.

Those who can still leave Northern Gaza are now streaming south.

GEOFF BENNETT: Leila Molana-Allen again starts our coverage, after spending much of the day in Gaza with the Israel Defense Forces.

An editorial note: The IDF reviewed the video that "NewsHour" recorded in Gaza, they say, for the operational security.

The IDF had no editorial role in this story prior to its broadcast.

LEILA MOLANA-ALLEN: There are no roads left here.

As we cross the border into Gaza, leaving the same dirt track hordes of Hamas terrorists used to invade Israeli towns on October 7, the landscape becomes little more than dust.

Towns in this area were flattened as Israeli troops fought Hamas militants in the early weeks of the war.

We were given access to embed with the IDF inside Gaza, subject to Israeli military restrictions.

So that's the border over there.

LT. COL. GILAD PASTERNAK, Brigade Commander, Israeli Defense Forces: Yes, you can see the border.

You can see all the kibbutzes that have been attacked.

LEILA MOLANA-ALLEN: The IDF believes Juhor ad-Dik, a farming village once home to 5,000 people, was a key planning and staging outpost for the attacks.

LT. COL. GILAD PASTERNAK: A lot of outposts and a lot of anti-tank missiles that we found over here.

And many houses was booby-trapped with wires that exploded before the IDF soldiers could get inside.

LEILA MOLANA-ALLEN: Gilad says this is just one the many locations where tunnels have already been found and capped, but they know that they're connected to hundreds of miles more beneath the strip.

LT. COL. GILAD PASTERNAK: We're speaking about hundreds of open holes and tunnels that Hamas has built in the ground Hamas has built during the years in order to make all of Gaza a huge terror compound.

Only in this village, we found five pit holes, three main tunnels under civilians houses.

LEILA MOLANA-ALLEN: They say they can't show us these tunnels because there's a risk there are still active fighters inside.

LT. COL. GILAD PASTERNAK: Each tunnel has a different purpose.

For example, the tunnels we found here what we call closing tunnels, closing to the border, close to the IDF soldiers, in order to infiltrate them or to flank them in beneath and to strike them.

It's very likely to say that we are standing right now above tunnels we haven't found yet.

But we're to find it sooner or later.

LEILA MOLANA-ALLEN: It's hard to believe anyone could live here again.

The scale of the destruction here and in so many other villages along Gaza's border with Israel is complete.

Every house is gutted.

The U.N.s humanitarian office says 45 percent of Gaza's homes have already been damaged or completely destroyed.

As we roll further inside the strip, the navigator tracks the terrain through the sights of this armored vehicle, a wasteland of twisted metal and dirt, almost unrecognizable as an area where thousands of people once lived.

Suddenly, an urgent call on the radio.

A soldier has been wounded at the location we're headed to.

The team has just been told that one of the soldiers securing the humanitarian corridor has been shot in the neck, perhaps by a sniper.

They're trying to organize a evacuation by helicopter.

LT. COL. GILAD PASTERNAK: We're connected between the wounded soldier, the chopper, and in the car.

The convoy is making its way with the casualty on it toward the border.

LEILA MOLANA-ALLEN: Ahead, emerging over the crest of a military outpost, Gazan civilians on foot weighed down not by the meager bags they carry, but by weeks of constant fear and devastating loss.

As Israel continues its bombardment of Gaza by air and by land, behind me, you can see hundreds of Gazan civilians trying to evacuate down the main north-south highway.

They're weary and hungry, and, in the background, you can hear gunfire, which the Israeli military tells us is Hamas militants fighting with Israeli soldiers as they try to stop civilians evacuating.

Soldiers take cover to secure the passage.

The IDF call out regularly in both Hebrew and English, hoping to find hostages hidden in the crowds and signal to them to come out.

Four-hour daily combat pauses for evacuations have been agreed.

There's no sign of them yet.

Abu Shady says his community has suffered beyond imagining and now faces a long walk into the unknown.

ABU SHADY EL-HAYEK, Displaced Gazan (through translator): We have no food or water and we are displaced from our home.

Our building was destroyed with our belongings inside.

I'm fleeing with no clothes.

We are all without clothes and don't know what to do.

What can we do?

LEILA MOLANA-ALLEN: What condition are the Gazan civilians that you're seeing crossing here in?

LT. COL. GILAD PASTERNAK: I think that the people over here know that they have an opportunity to protect their lives.

They are waiting for them on the southern part of the strip with havens, with tents, with water, with food.

LEILA MOLANA-ALLEN: These people hope and have been told that by fleeing south they may lose their homes, but they will save their lives.

But Gazans who have already reached the south say the bombardment there is nearly as bad and the living conditions unbearable.

Anwar fears the worst is yet to come.

ANWAR ABU AL-TARABISH, Displaced From Al Shifa Hospital (through translator): I was in Al Shifa Hospital.

I was expecting it to be a safe place for us and other citizens.

But it was not a safe place.

This place is not safe either.

There is bombing everywhere.

There was no mercy.

These are mass massacres.

LEILA MOLANA-ALLEN: The IDF says it's doing its best to minimize casualties, but has no choice but to eradicate Hamas, in spite of the civilian toll.

Israelis, often at odds over internal politics, are almost universally united over this war, which they see as a fight for their country's very survival.

Gazans caught in the crossfire will soon have no country left.

For the "PBS NewsHour," I'm Leila Molana-Allen on Salah al-Din Street, the Gaza Strip.