Emergency services were called to Burnt Oak Broadway shortly after 11:50 BST
A 22-year-old man has been arrested on suspicion of the murder of a woman who was stabbed in north-west London.
The woman, in her 60s, was treated by paramedics at the scene in Edgware but died shortly before midday.
The suspect was arrested in the Colindale area, in what the Met Police described as a “significant development”.
Police are still trying to find the woman’s family, and a crime scene remains in place.
‘Shocking attack’
The Met has not said whether the suspect and victim are known to each other and has asked the public not to speculate.
Supt Tony Bellis, from the North West Command Unit, said the arrest came as a result of “fast-time work from specialist detectives”.
He added: “A family has been left devastated by this shocking attack and my thoughts are with them at this unimaginably difficult time.”
Pictures from the scene showed at least six emergency service vehicles inside a police cordon on Burnt Oak Broadway.
Supt Bellis said there would be an increased police presence in the area over the coming days.
