Nine-year-old Mohammad Hadaf sustained severe injuries in an Israeli air strike during the 2014 Gaza War when he was six, leaving him paralysed, blinded, and unable to speak.

He finally succumbed to his wounds on December 6, last year.

"I hope nobody will ever have to experience what I did," said Saleh, Mohammad's father.

"I had to feed my son through a tube. When you see your son in this kind of pain, you also feel the pain with him," he told Al Jazeera.

Mohammad is among more than 500 child victims of the 51-day Israeli offensive, in which more than 2,000 Palestinians were killed.

When Israel began bombarding Gaza, Saleh said he was afraid for his children because "our house was not well-built and could not survive the bombs".

With his wife Nisrin and five children, the family moved to a relative's home in Khan Younis.

Their home in al-Qarara was bombed by Israel a few days later.

'It was hard to accept his death'

During a ceasefire, they returned to collect whatever belongings they could find. Saleh wanted to go alone, but his children and wife begged to join him.

An hour after they arrived, Saleh saw smoke. Israeli forces had fired a missile in front of his home.

"I saw all of them fall down to the ground," he said.

Three of Saleh's young neighbours - aged eight, 15 and 19 - were on the street at the time. They were killed instantly.

Saleh, Nisrin and four of their children were injured.

Three-year-old Ayesh was paralysed on one side of his body. He has since healed.

Five-year-old Remas sustained an injury to the skull.

Mohammad was hit in the abdomen and spine, and had to be resuscitated during surgery because of a lack of oxygen to the brain.

Accompanied by his aunt, the child travelled to Turkey for further treatment.

Mohammad spent years rotating between hospitals and undergoing surgeries, but continued to deteriorate.

He became blind and lost the ability to speak or move.

The financial burden wreaked havoc.

"If I were to try and explain to you all the money I spent on Mohammad's treatment - his wheelchair, medicine, special food - I wouldn't be able to finish," said Saleh.

None of Gaza's political factions helped the family because they are not associated with a specific party, he claimed.

"We spent everything we had on Mohammad's treatment. We have nothing left," said Saleh, who was with his son when he died.

"Even though I knew how badly he was doing, and that he wouldn't last much longer, it was hard to accept his death. I loved him so much," Saleh told the B'Tselem rights group.

'My children will never be the same'

Amit Gilutz, B'Tselem spokesperson, told Al Jazeera that "one of the most horrifying hallmarks" of Israel's assault on Gaza was its targeting of residential homes.

This policy resulted in more than 1,000 Palestinians, including hundreds of children, being killed.

They took "no part in the fighting", said Gilutz.

The trauma continues to haunt the Hadaf family.

"We don't even own a television in the house, because we cannot deal with seeing bad things anymore," said Saleh.

Jess Ghannam, a clinical professor of psychiatry at the University of California - San Francisco, told Al Jazeera that he has documented "many cases of severe PTSD" in Gaza following Israeli bombardment in 2012, from 2008 to 2009 and most recently in 2014.

"Many Palestinians living in Gaza exposed to war develop symptoms of PTSD that include flashbacks, anxiety, and hypervigilance," he said. "They live with daily distress and the expectation that something bad will happen, and this results in fatigue and general ill health."

Saleh is among those who live in constant fear, saying: "We feel like another war will break out at any moment."

Ghannam said this sentiment is common among traumatised Palestinians.

"Because of the occupation and siege, there are continuous reminders of war so that the healing process can never fully be realised," he said.

"Palestinians in Gaza live in constant fear of another attack and do not have any chance to process events and heal. It is a constant state of psychological distress and siege."

Children struggle the most, said Saleh.

"They become so scared when they hear the Israeli planes above us at night. Sometimes they wake up at night crying," he said.

"They are always afraid. My children are completely different than how they were before the war. Sometimes they have problems focusing. You have to ask them questions more than once in order to get an answer.

"All of these memories of the war and Mohammad's suffering will stay with them for the rest of their lives. They will never be the same."