On his way home from work late Friday night, 20-year-old Jimi jumped into the River Thames to save a woman who had fallen in.
"He had knives in both hands and, upon seeing me with the narwhal tusk, pointed at his midriff," Darryn Frost told Britain's Press Association.
Two people were killed last week when an Islamic extremist launched a knife attack in central London.
The Secret Barrister, an anonymous legal blogger, claimed Boris Johnson's 16-part Twitter thread was "basically copied and pasted" from a post they had published.
One of the men seen on video subduing the knife-wielding suspect has been identified as James Ford, a convicted murderer on day release who was attending the same prison education conference as the attacker.
Usman Khan, who was shot dead Friday after launching the London Bridge attack, was one of nine men who were convicted back in 2012 of plotting to attack the London Stock Exchange.
Police confirmed the incident as terror-related, and said the suspect was wearing a hoax explosive device.
The preacher still has dozens of sermons on the video-sharing platform, months after the deadly assault.
"This is what they want. This is what they are aiming for."
Sadiq Khan has called on the British government to cancel Trump's visit later this year.
Former Secretary of State, John Kerry, and other counter-terrorism experts say the U.K. hasn't integrated Muslims into society as well as the U.S.
Trump tweeted: "At least 7 dead and 48 wounded in terror attack and Mayor of London says there is 'no reason to be alarmed!'"
Revellers shouted and threw barstools at the three attackers, who killed seven and injured 49.
The woman from Canada moved to Europe to live with her fiancé, her family said in a statement.
One person was hit with a stray bullet and is being treated at hospital along with more than 40 other people injured in a knife and van attack in London Bridge and Borough Market.
Like the Bataclan and Manchester Arena, Borough Market was targeted for being a place of celebration and joy.
Tourists and locals spent the night in hotels after the attack that killed seven people and injured dozens.
On social media, people reported being told to go into bars and restaurants and and take cover under tables.