Saifeddin Abutaha, an aid worker for World Central Kitchen, was on his way home to see his mother when an Israeli missile struck the car he was driving in a humanitarian convoy last week.

Mr. Abutaha, 25, doted on his parents, and he texted them frequently while out delivering aid across the Gaza Strip, which is on the brink of famine after six months of war. In his final hours, he had pivoted between delivering food and making family Ramadan plans, his brother, Abdul Raziq Abutaha, said in an interview.

But since his death on Apr. 1, their mother, Inshirah — who once daydreamed of seeing Saifeddin get married — has been unable to accept that he is gone.

“She still has not eaten anything since he died,” said Abdul Raziq, 33. He said that she keeps saying, “‘He will be back soon, maybe for Eid’” — the holiday that marks the end of Ramadan. It begins on Wednesday. Saif will not be there.

The killing of seven World Central Kitchen employees in the Israeli attack on April 1 has drawn international outrage, especially from the countries from which six of them hailed: Britain, Poland, Australia, Canada and the United States.

Mr. Abutaha, a Palestinian from Gaza, also perished in the attack. His death highlighted the grim fact that most of the more than 200 aid workers who have been killed since Israel’s bombardment of Gaza began have been Palestinian, according to United Nations Secretary General Antonio Guterres. He called last week for an independent investigation into each of their deaths, which have drawn less attention than the killing of foreign aid workers.

Palestinian workers form the backbone of the humanitarian response in Gaza, as do local employees in any war zone or disaster area where aid groups operate. They provide vital connections and on-the-ground expertise to foreign staff members unfamiliar with the area, and make it possible for them to implement relief projects and communicate with the people they are serving.

Mr. Abutaha worked for World Central Kitchen as a driver and translator, helping its staff navigate the bureaucracy, political climate and city streets of the places where he grew up, and where until the missile attack it was providing critically needed aid. His affiliation with a well-known and well-organized group brought with it something uncommon in Gaza these days, his family said: a semblance of safety.

“We never, ever thought Saif would be hit or killed,” Abdul Raziq said last week. “This is an international humanitarian group that had a very high coordination with Israel and its army.”

That coordination did not protect Mr. Abutaha and his co-workers. An internal investigation by the Israeli military concluded their killings were a “grave mistake” caused by a number of failures and broken protocols, and found that officers ordered the strikes on the aid convoy in part on the basis of insufficient and erroneous evidence that a passenger in one of the cars was armed.

Israel said several military personnel involved in the attack had been reprimanded or dismissed.

But José Andrés, the high-profile celebrity chef who founded World Central Kitchen, has demanded an independent investigation. On Sunday, in an interview on ABC’s “This Week,” he said “the perpetrator cannot be investigating himself.”

“Obviously this was targeted,” Mr. Andrés said of the killings, which were carried out by three separate strikes, one after another, that hit three vehicles carrying the workers. “We could argue that the first one, let’s say, was a mistake. The second? The third?”

Israel began its military campaign in Gaza after an Oct. 7 attack led by Hamas killed about 1,200 people near the border, according to Israeli authorities. Israel says its aim is to destroy the group.

But while the war has so far killed more than 33,000 people in Gaza, according to local health officials, Hamas has not been destroyed. Its most senior leaders remain alive, its fighters remain active, and it has regrouped in parts of Gaza.

Abdul Raziq Abutaha said that before the war began his younger brother had been poised for as bright a future as any young person could hope for in the Gaza Strip, which has been under a punishing Egyptian and Israeli blockade since Hamas took power there in 2007.

Saif attended the Ajman University in the United Arab Emirates, Abdul Raziq said, and had worked in the U.A.E. until his father asked him to return home in 2020. He wanted Saif to help run the family business, a flour mill.

But running the mill became impossible during the war after Israel’s attacks destroyed much of Gaza’s civilian infrastructure, and left the company without basic raw materials like electricity or flour.

One day, though, World Central Kitchen staff members visited the family warehouse and liked what they saw. They chose the site to serve as their Gaza headquarters, after coordination with the Israeli military, Abdul Raziq said.

The aid workers began living in an apartment inside the factory, and they and the family soon grew close, sharing meals and bonding over the traumas of war.

“We loved them and they loved us,” Abdul Raziq said.

The World Central Kitchen staff asked Saif to translate for them during a meeting, and then hired him as a driver and translator. He and the foreign staff members quickly became inseparable, his sisterAmani, said in an interview with Al-Ghad TV, an Arabic-language channel.

“He was always with the foreigners, translating for them, and he would go to collect aid,” she said. “Because he lived in Gaza and knew the streets of Gaza well, he was a driver.”

Abdul Raziq said his brother was “overjoyed” to find a job helping victims of the war, and that their family found a kind of blessing in the fact that “he died while he was on duty feeding poor and starving people” during the holy month of Ramadan.

On the day Saif died, the small World Central kitchen group had left their facility in the southern Gaza Strip and traveled north, Abdul Raziq said. Saif checked in with his family throughout the day; his sister, Amani, said her last exchange with him was at 4 p.m., when Saif sent her a selfie he took while he waited for a cargo ship to arrive.

“I told him to take care of himself and may God protect him,” she said. “He replied, ‘I rely on God.’ I did not know that soon God would take everything.”

Saif also texted Abdul Raziq to say he was headed home to prepare for the next day’s Ramadan fast with their mother. He then sent one last text to their mother, asking, “Did you go to sleep yet, my mom?”