AMNA NAWAZ: Monday marks one year since the October 7 Hamas terror attacks on Israel.

Over this last year, the Israeli bombing and invasion of Gaza has exacted a terrible price on Gaza's people, with an estimation that one out of every 20 people has been killed or wounded.

"News Hour" videographer Shams Odeh in Gaza worked with producer Zeba Warsi and Nick Schifrin to bring us this report on a year in hell.

NICK SCHIFRIN: To this day, Mohammed Mahdi Abu Al-Qumsan cannot fathom his incomprehensible loss.

He walks us into his threadbare home and life, a donated canvas shelter, with sorrowful reminders, the doll that will never be held, the clothes that will never be worn.

MOHAMMED MAHDI ABU AL-QUMSAN, Gazan Resident, Lost Wife and Twins (through translator): I don't even have one photo of me and my children.

I had only left the house to get their birth certificates.

I ended up getting their death certificates too.

NICK SCHIFRIN: In August, horror.

His wife of one year, her body under the shroud, her name in pen, Dr. Jumann Arfa, and 3-day-old Asser and Aysel, the family says all killed in an Israeli airstrike.

In Gaza today, death can arrive as life begins.

And photos of births, are the only photos he will ever have.

MOHAMMED MAHDI ABU AL-QUMSAN (through translator): I was excited to leave the hospital to go and show my wife the birth certificates because she chose their names.

Only five minutes later, I started the process to get their death certificates.

NICK SCHIFRIN: Arfa was a pharmacist at a private clinic.

The twins were their first-born.

And like everyone here, in the last year, the family fled from multiple homes, first from Gaza City, then to Rafah, and then back to Deir al Balah, in search of unobtainable safety.

On Facebook, Arfa used to write about the war's victims, until she became one.

MOHAMMED MAHDI ABU AL-QUMSAN (through translator): I need a court of law to find how a woman who was living in a safe home, who had recently given birth was killed in this way.

Children are not at fault.

We're merely civilians.

We're not involved in other activities.

Don't we deserve to live in peace, without fear?

NICK SCHIFRIN: But Gaza is stalked by fear and dominated by death.

The Abed kids, Hala, Ghazal, Mohammad, and Salma, are among tens of thousands of orphans, adopted by their uncle after his brother, their father, Majdy, was killed last October.

NABIL HASSAN ABED, Gaza Resident, Lost Brother (through translator): Majdy was my brother, my friend, my everything.

I was devastated.

NICK SCHIFRIN: The siblings survived by chance.

Their mother unknowingly saved them.

HALA MAJDY HASSAN ABED, Gaza Resident, Lost Both Parents (through translator): We were at home and then my mom asked us to go get her something from the store.

When we came back, we found the entire area destroyed.

NICK SCHIFRIN: They're grateful to have a place to live.

But what she really wants to have is her parents back.

We ask, "Do you miss them?"

This war started one year ago, when Hamas gunmen took over swathes of Southern Israel and killed 812 civilians and more than 400 security personnel.

Israel has pursued what it calls absolute victory over Hamas with a punishing air and ground campaign to eradicate Hamas and return the hostages.

It blames civilian deaths on Hamas.

BENJAMIN NETANYAHU, Israeli Prime Minister: Hamas places its weapons, it's terrorists in hospitals, schools, mosques and throughout civilian areas.

They do this in order to win immunity and to maximize civilian casualties.

NICK SCHIFRIN: Gaza's Health Ministry, which answers to Hamas, says 140,000, or more than 5 percent of the Gaza Strip, have been killed or wounded, 900 families wiped off entirely from the civil registry, and in more than 1,300 cases, only one family member survived, creating the macabre label wounded child, no surviving family.

But all the numbers may yet prove an undercount.

DR. KHALIL AL-DAQRAN, Gazan Health Ministry Official (through translator): There are 8,000 to 10,000 martyrs missing since the beginning of these attacks.

NICK SCHIFRIN: Dr Khalil Al-Daqran works at Central Gaza's Al-Aqsa Hospital, one of the few hospitals still functioning.

He helps the Health Ministry publish its daily death toll, 90 percent of whose names have been confirmed.

It's a painstaking effort because many of Gaza's more than two million displaced don't have I.D.s.

DR. KHALIL AL-DAQRAN (through translator): In the case of those martyred who are not identified in hospitals, we take several steps like asking questions of the families.

Many times people who come to the hospital have no identification since occupation forces destroyed their homes and whatever was in it.

NICK SCHIFRIN: And destruction breeds despair.

Four-year-old Raghad Ismail Al Khouly holds her father tight, hoping he can heal her.

But Ismail Al Khouly feels helpless because he can only provide comfort, no cure.

Raghad Al Khouly has cancer, tumors under both eyes that cause severe pain.

ISMAIL AL KHOULY, Father of Child in Need of Medical Care (through translator): I feel like my heart is being ripped apart.

I wish I could do something for her.

I swear I cannot.

I swear I can't do a thing.

NICK SCHIFRIN: Like any sick child, cartoons distract until her eyes feel strained.

So, her best chance for treatment is outside.

But the outside world is almost completely inaccessible.

ISMAIL AL KHOULY (through translator): Consider her like one of your daughters.

If we delay her treatment anymore, it could lead to her blindness.

She was a smart girl.

She'd run and play but ever since getting the tumor, she's completely, completely changed.

NICK SCHIFRIN: One year later, Gazans' infrastructure and lives are unrecognizable.

They have lived through multiple wars.

But after this one, nobody will be the same.

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

AMNA NAWAZ: On Monday, Nick will speak with families of Israeli hostages and with a released hostage looking back on this traumatic year in her own words.