As more details emerged about Friday's deadly knifings - carried out, police said, by 28-year-old Usman Khan, previously convicted and jailed for a terrorism plot - new profiles in courage appeared in the British press. They were bolstered by amateur video clips, witness statements and paeans by the London mayor and the British prime minister.
British media reports also said that one of the people who intervened in the attack is a convicted murderer.
The intervention of several members of the public appears to have stopped the attack from being far worse, witnesses said, as Khan was seen running onto London Bridge with a large knife in his hands.
He was then confronted by at least three men. One jabbed with the decorative narwhal tusk. Another let loose a spray from a fire extinguisher. A third used his fists and feet.
The attacker was later shot and killed by police.
Queen Elizabeth II, in a statement, praised their bravery. "I express my enduring thanks to the police and emergency services, as well as the brave individuals who put their own lives at risk to selflessly help and protect others," she said.
The mayor of London, Sadiq Khan, no relation to the dead attacker, said he was in "awe of the people who ran toward danger to keep us all safe."
Asked about reports that one of the defenders was from Poland - whose identity has not been made public - the mayor confirmed he was a Londoner of Polish origin.
"One of the great things about London is its diversity, so I'm not surprised at all. When I say 'the best of us,' I include E.U. citizens as well," the mayor said.
Many social media posts also pointed out that campaigners for Brexit used stereotypes such as the "Polish plumber" and other tropes about workers coming to Britain from across the European Union.
British Transport Police said Saturday that another man widely seen in social media videos carrying away a large, bloody knife seized from the assailant was a plainclothes police officer who helped detain the suspect. The police asked that the news and social media obscure his image and do not name him.
It all began just before 2 p.m. Friday, when Khan allegedly entered the historic Fishmongers' Hall beside the London Bridge.
Police said Khan was attending an event hosted by Learning Together - a Cambridge University-backed program that works to reeducate and socialize prisoners - when he launched the attack.
In dramatic footage shared widely online, three individuals - the one wielding the tusk, the one with the fire extinguisher, and the one who was seemingly armed with nothing but quick reflexes - brought the attacker to the ground.
The assailant was shot dead after he fatally stabbed a man and a woman. Three others were wounded.
The assailant was wearing what appeared to witnesses as a "suicide vest." London's mayor pointed out on the BBC that they would have had no clue at the time that the explosives were fake.
"They had no idea whether this man had a bomb you could detonate by pressing a button, they had no idea how many other people were involved," he said. "What do they do? They run toward him."
The man with the narwhal tusk was identified only by the name Luckasz, according to British newspaper the Times, which contacted his colleague. Poles on social media pointed out that his name was likely spelled Lukasz.
He reportedly took the tusk from a wall in Fishmongers' Hall, where the Times said he works setting up events and managing porters.
A narwhals is a type of whale sometimes called "the unicorn of the sea" for its distinctively long tusk.
The Polish man's colleague told the Times: "Being stabbed didn't stop him giving him a beating. Luckasz is a hero." He was "cut in the hand but not in critical condition."
Many on Twitter pointed out that the man was a European Union citizen and praised immigrants. Others suggested the act could help unite the country.
One person wrote, "If a Polish chef attacking a terrorist with a whale horn can't unite our country I don't know what can."
Meanwhile, several British media outlets reported that another man who helped subdue the attacker was 42-year-old James Ford, who was jailed for life in 2004 for the murder of 21-year-old Amanda Champion, who had learning difficulties.
According to British media reports, Ford was believed to be serving the final days of his sentence at an open prison in Kent and was on London Bridge as the attack unfolded and that he was attending the same conference as the attacker.
"He is not a hero. He is a murderer out on day release, which us as a family didn't know anything about. He murdered a disabled girl. He is not a hero, absolutely not," Champion's aunt, Angela Cox, told the Daily Mail on Friday. "I don't care what he's done today, he's a murderer."
It was the not the first time that bystanders have fought back against terrorism.
In August - in a video shared to Twitter and viewed more than 4 million times - people used chairs and a milk crate to trap a man during a stabbing rampage in Sydney.