The three terrorists were dead - eight minutes after they drove their van into London Bridge and started stabbing anyone they could find.
Earlier Wednesday, a 30-year-old man was arrested on suspicion of terrorism-related offenses following a raid in Ilford in East London, which has emerged as the apparent hub for the attack plot.
Both Butt and Zaghba were known to British law enforcement, raising questions about whether anything could have been done to prevent the assault.
It was not immediately clear how the three knew each other, but Collina said one of her son's friends recognized one of the other attackers, though it wasn't clear which one that was.
On Thursday a British Transport Police officer stabbed in the eye during the attack described his anguish at not being able to do more to help those killed and injured.
The neighbour said the road was cordoned off and went into "lockdown". "His courage to defend another person serves as a reminder to stay united before the scourge of terrorism", said a Spanish Foreign Ministry statement. Italian officials said suspicions about him were shared with British authorities and his name was listed in the Europe-wide intelligence-sharing system.
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Removing the record seventh FA Cup winner's medal from his pocket, Arsene Wenger was gratified and yet apprehensive. Arsenal have won the FA Cup three times in the last four seasons and Ramsey has now bagged the victor twice.
Along with Rachid Redouane, 30, the men died in a hail of police gunfire after spending eight minutes laying waste to the nightlife of south London.
The information offered so far by British authorities on Echeverria's death has been "sufficient and correct", said Ana Echeverria, the youngest sister of the victim.
The Times newspaper also said it had obtained footage of the men laughing and joking five days before the attack as they met outside the Ummah Fitness Center, a gym in east London where Butt trained.
Associated Press writer Nicole Winfield in Rome contributed. However, she said she and the police assumed he wanted to eventually go to Syria, given he only had a one-way ticket to Istanbul and a small backpack.
Butt had appeared in a television documentary called "The Jihadis Next Door", as one of a group of men who unfurled an Islamic State flag in a park and who had connections with known radical preachers. Two people believed to have documents linked to Redouane were arrested in Ireland, though only one remained in custody Wednesday.
Much of the area, which had been closed since the attack occurred last Saturday, has now reopened, according to police.