British Muslim organizations were quick to condemn the attack.
"We must come together, isolate those who believe that extremism and violence are acceptable, and work to ensure that they meet the full force of the law," Fiyaz Mughal, the director of Faith Matters, said in a statement. "We as the Muslim community will work against anyone who promotes such hatred."
Still, at a moment when much of the country was upset by a crime clearly designed to shock, there were signs of notable bravery.
After the attack, a mother of two named Ingrid Loyau-Kennett approached one of the attackers and engaged him in conversation. Loyau-Kennet can be seen in a photograph calmly talking to the man. He was carrying a bloody knife -- she carried only her resolve.
"I just talked to him. He looked like a normal guy. He wasn't high, he wasn't on drugs. A normal guy pissed off with the fact [as he said], 'Muslim women and children are dying in their countries by the hand of white men,'" she told ITV's Daybreak. " He was very, very close to me. He was almost touching me ... I asked him, what's the point. [He said] 'war in London.'"
ITV presenter asked her why she wasn't scared. "Better me than a child," Loyau-Kennet said. "Because, unfortunately, there were more and more mothers with children stopping around. So it was even more and more important that I talk to him and then ask him what he wanted."
Cameron called Loyau-Kennet a hero.
"When told by the attacker he wanted to start a war in London, she replied, 'You are going to lose. It is only you against many,'" Cameron said. "She spoke for us all."