Friends of a shop worker fatally attacked in a row over cigarette papers described him as "honest" and "hard-working", as police launched a murder investigation.
Vijay Patel, 49, was critically injured by a single blow on Saturday outside the shop in Mill Hill, north London, police said.
Three teenage boys are suspected of targeting the father-of-two after he refused to sell them the items due to concerns over their age.
Mr Patel, from Colindale, north London, succumbed to his injuries in hospital on Monday afternoon.
A 16-year-boy has been arrested on suspicion of murder, as police continue to hunt for two other suspects.
Mr Patel's friends spoke of their devastation on Tuesday.
Jagmeet Sethi, 27, who has worked in the convenience shop alongside Mr Patel for almost a year, said he struggled to believe his friend could "lose his life only for one Rizla, nothing else".
"It's very hard to accept this," he said. "He's not here anymore. It is very difficult."
He said he was still expecting Mr Patel to walk through the shop door.
He said Mr Patel had built a reputation among customers as a "very helpful, quiet, down-to-earth" man who would help shoppers carry their bags if they were struggling.
"He was a very nice guy," he said, "a good-natured guy. If you buy something he would go with you to your car and give it to you."
"It is unacceptable to us that he is no more."
Workers in local Mill Hill businesses also spoke of their shock.
Amjad Salaam, 72, who works at a nearby dry cleaners, described Mr Patel as an "honest" and "hard-working" man who would come to his shop to "say hello" from time to time.
"You can't even think of any right words to say about it," he said. "It's just dreadful."
"They have lost a loyal worker."
He said Mill Hill is a "very nice, pleasant area", and the local community would be stunned by the killing.
There is some "boorish behaviour" from local schoolchildren, he said, but it usually just amounts to "shouting and swearing in the street".
Ellen Toupchaini, 25, who owns an organic cafe over the road, also said it was a "really nice area".
The killing is a "big shock to everybody", she said.
"I think it was just children who were just completely mindless."
"They're going to have to pay for that for the rest of their lives," she added.
Tributes outside a shop on The Broadway in Mill Hill, north London
Zain Dar, 23, who works in a nearby mobile phone shop, said: "It's worrying that something like that can happen in the area."
He said the attackers "took an innocent life for no reason" and hopes they serve a long prison sentence.
Police officers found Mr Patel lying on the pavement outside the shop after they were called at 11.45pm on Saturday evening, Scotland Yard said.
He was rushed to hospital by the London Ambulance Service.
Detectives appealed for help identifying the suspects, and asked anybody who may have mobile phone footage or images of the incident to contact them.
They have also been conducting door-to-door inquiries and gathering CCTV images from the scene.
The group were seen running off along The Broadway, in the direction of Mill Hill Broadway Station, after the attack, police said.
The suspects were described as three black males, with one wearing a red sweatshirt, black jeans and white trainers, another wearing a dark grey or black tracksuit and black trainers and the third a dark-coloured hooded sweatshirt and black jeans.
By Jack Hardy
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here