Nasrat Ahmad Yar, an Afghan who spent most of his adult years working with the US military in Afghanistan, has been shot dead in Washington, official said.
Ahmad Yar, who escaped to the US in search of a better life for himself and his family, was working as a ride-share driver.
Worried about making rent, he went out driving before he was shot and killed on Monday night.
No suspects have been arrested, but surveillance video captured the sound of a single gunshot and four boys or young men were seen running away.
Police have offered a $25,000 reward for information leading to an arrest.
"He was so generous. He was so nice. He was always trying to help the people," said Rahim Amini, a fellow Afghan immigrant and longtime friend.
He said Ahmad Yar always reminded him, "Don't forget the people left behind."
Jeramie Malone, an American who came to know Ahmad Yar through her volunteer work with a veteran-founded organisation bringing former Afghan interpreters to safety, also was struck by his generosity.
"He always wanted to be giving more than he was receiving and he was just really extremely kind." In America, Malone said, "all he wanted was a chance."
Amini said Ahmad Yar had worked for the US military for about a decade as an interpreter and doing other jobs, seeing it as a way to help pave the way for the next generation in Afghanistan to have a better life.
While the US has had a Special Immigrant Visa programme for Afghans who worked closely with the US government to come to America since 2009, Amini said his friend didn't want to apply right away, preferring to stay in Afghanistan, where he felt needed.
He remembered Ahmad Yar saying: "I have guys here I need to support. ... When I feel that they don't need my support, then I can go to America."
'I'm not safe here'
Ahmad Yar and his family went to the northwestern city of Mazar-e-Sharif, where he and his family were able to get on a flight to the United Arab Emirates and then eventually travel to America.
Even when laying low in Mazar-e-Sharif, Nasrat would go out of his way to assist other Afghans who also had come to escape the country — greeting them on arrival to the strange city, bringing their families to stay with his, and feeding them, while all waited for flights out, Malone said.
"Nasrat was very different, because even though he was needing help, he was always helping me," she said.
His eldest child, a girl, is now 13, and the others are boys, ages 11, 8 and just 15 months old.
The family went first to Pennsylvania, but Amini said his friend was robbed there and decided to move to Alexandria, in northern Virginia, just outside Washington DC.
Amini said Ahmad Yar told him he'd fled to the US "to be safe, and unfortunately, I’m not safe here."
In northern Virginia, they both ended up being ride-share drivers and lived about three kilometres from each other.
Like many in the Afghan diaspora there, they chatted throughout the day in a WhatsApp group text.
Amini said they spoke on Monday evening, and the next thing he knew, he was woken up by another Afghan friend who'd somehow heard that Ahmad Yar had been killed.
In disbelief, Amini began frantically calling his friend. But it was the police who finally answered the phone: "The police officer said: ‘I’m sorry. Unfortunately, he’s not alive anymore.’"
The police said in their report that they responded to a call about an unconscious person and found Ahmad Yar's body.
They rushed him to the hospital, where he was declared dead.
On the surveillance video they released, one of the four suspected attackers shouted, "You just killed him. " Another answered, "He was reaching, bro."
Rising crime rates in capital
The US capital has struggled to handle steadily rising crime rates, with murders and carjackings mostly to blame.
Homicides are up 14 percent compared with this time last year.
Early on Wednesday, nine people enjoying the Independence Day festivities were shot and wounded, police said.
Since Ahmad Yar's death, condolences and donations for his wife and children have been flowing into fundraisers set up on GoFundMe and Facebook.
Between learning a new language, finding a job and struggling with government bureaucracy to file immigration papers, Afghan families face a lot of hardship even after getting to the United States.
Many of the men work for Lyft or Uber to make ends meet.
Ahmad Yar will be laid to rest on Saturday.