WARNING: This story contains graphic descriptions of injury and death.

Adam, 11, smiles brightly in the face of unimaginable horrors.

The Palestinian boy is recovering in Gaza's Nasser Hospital from injuries sustained in a May 23 Israeli airstrike on his home that killed his father, who was a doctor, and all nine of his siblings. 

"Adam is doing remarkably well. He is much, much better than I thought he would [be]," Dr. Graeme Groom, the British orthopaedic surgeon caring for the boy, told As It Happens host Nil Kӧksal.

"He has an angelic little face and it lights up in the most gorgeous smile."

Adam and his mother, a pediatrician who was working at Nasser when her husband and children were struck, are now their immediate family's sole survivors.

And their situation, says Groom, is not remotely unique in Gaza.

'Like a crushed can of sardines'

Adam's father, Dr. Hamdi Al-Najjar, died on Saturday from brain and internal injuries sustained in the strike on his home in Khan Younis.

His nine other children — Yahya, Rakan, Ruslan, Jubran, Eve, Rivan, Saydeen, Luqma and Sidra — were all killed in the same strike.

When their mother, Dr. Alaa al-Najjar, heard about the airstrike, she ran on foot from the hospital to her home, Hamdi's niece, Sahra Al-Najjar, told CBC News last week. 

But she was too late. When she arrived, her home was reduced to rubble, and her children's bodies were so badly burned, she couldn't tell them apart. 

"Who were you targeting? Kids?" Sahra said. "This is your strength?

WATCH | 9 children, all siblings, killed by Israeli airstrike: 

Airstrike kills 9 children of Gaza doctor as Israelis demand end to war

The Israeli military says it’s reviewing an airstrike that killed nine children of a doctor working at a hospital in Khan Younis, in southern Gaza, as patience with the war grows thin among some Israeli citizens demanding an end to the fighting and a return of the remaining hostages.

The youngest of the slain children was six months old, and the oldest was 13, according to Al-Najjar's brother, Ali Al-Najjar.

He, too, rushed to the scene of the bombing that day. 

"The house was like a crushed can of sardines," he told CBC News the day after the strike, while his brother was still in intensive care.

The Israeli military has confirmed it conducted an airstrike on Khan Younis that day, but said it was targeting suspects in a structure that was close to Israeli soldiers.

The military is looking into claims that "uninvolved civilians" were killed, it said, adding that the military had evacuated civilians from the area before the operation began.

Sahra says there's no good reason her uncle and his family should be targeted. 

"He was very straight," she said. "He was very famous in the medical field. He had nothing to do with any political movements."

Dozens of Palestinians marched in Hamdi's funeral in Gaza on Saturday.

Doctor has served in 14 wars, but none so bad as this

Groom says he's been in regular contact with Adam's mother, though their conversations have focused on her surviving son's health. 

"She's poised and professional," he said. "She is keenly interested in Adam and his progress."

Groom says whole families being nearly wiped out has become par for the course in Gaza. He works for the charity Islamic Help U.K., and says he's served in 14 global conflicts. 

"If we put all the others together, it would not come close to matching this," he said. "The number of injured, the appalling nature of their injuries, the inevitable long-term disability outstrip anything we have encountered to date — and I've had a long career looking after the wounded of many wars."

Just last week, he says, he operated on a seven-year-old boy who lost both of his parents and all of his siblings but one. At night, he cried out for a mother who was already gone.

"Every operating [room] has stories like that," he said. "When I speak to Palestinian friends and colleagues about this, they shrug and say, 'This is our life.'"

Israel began its offensive in Gaza in response to the Hamas-led attack on southern Israel on Oct. 7, 2023, which  killed 1,200 people, mostly civilians, according to Israeli tallies, and saw 251 taken as hostages into Gaza.

Israel's campaign has devastated much of Gaza, killing more than 54,000 Palestinians, according to Gazan tallies, and left huge swaths of the territory, including schools, hospitals and residential buildings, in ruin. 

The International Court of Justice is investigating whether Israel's actions in Gaza constitute a genocide, an allegation Israel strongly denies, and which has been repeated by human rights group Amnesty International. 

Last month, Canada joined Britain and France in threatening Israel with sanctions if it does not stop a renewed military offensive in Gaza and lift aid restrictions.

That smile again 

As for Adam, Groom says he's making a remarkable recovery.

When the child first arrived in the operating room just over a week ago, he was filthy and badly wounded, his body peppered with penetrating wounds from the force of the explosion.

He was bleeding from both ears, the result of a cranial nerve injury, and his left arm and wrist were broken.

Groom says they thought they would have to amputate his arm, but in the end, they were able to save it. 

Adam speaks English well, says Groom, so he's able to communicate clearly with him. But he's not sure how much the boy understands about what's happened to his family. 

"Our conversation is at a functional level. I try to make friends with him. I try to make him confident when he sees me," he said.

"And I have an absolutely certain way of producing this glorious smile that he has by offering him a chocolate bar."

With files from Mohamed El Saife, Yasmine Hassan and Reuters. Interview Graeme Groom produced by Chris Harbord