A mum-of-two who had her hand cut off and was left to die in a Greenford street has been named as Geeta Aulakh.
The 28-year-old, from Greenford, was on her way to pick up her two young boys aged eight and nine when the attack happened, and she was found in Braund Avenue just yards from her childminder's home.
She was suffering from a head wound and a severed hand by a passer-by who called 999 at about 7pm yesterday.
She was rushed to Charing Cross Hospital but died about four hours later at 11.20pm.
Colleagues at Sunrise Radio, in Bridge Road, Southall, where she worked as a receptionist, were devastated when they heard the news this morning.
A 29-year-old cameraman who asked not to be named said: "They told us in the best way they could, everyone in the building knew her, we were all in shock. She was just a happy, normal woman, nobody had a bad word to say about her. It's hard to explain how it feels, you just expect to walk in and see her sitting there."
Seema Sidha, a producer at Sunrise was one of the last people to see her alive.
The 31-year-old said: "I walked out with her and watched her cross the road to catch her bus. That was about 6.30pm, about half an hour later she was dead.
"She was a a happy person, always helpful and didn't seem to have any worries. We're all completely shocked."
The junction of Braund avenue and Verulum Road was still taped off this afternoon and specialist search teams were combing the area, checking in front gardens and under cars. An officer said they were looking for a weapon.
Police were also searching a house on Braund Avenue, forensics in white suits were seen entering today while neighbours said a dog team was sent in last night. The police would not say why the house was of interest.
Six men were arrested in connection with the killing this morning and police are appealing for witnesses.
Acting detective chief inspector Andy Chalmers said: "When the victim was found we know that a lot of people were in the street and that several people may have tried to administer first aid before the police or ambulance arrived.
"These people left the scene before speaking to police and I would ask that anyone who was there, or anyone else who has information about the incident, call us in the strictest of confidence."
Anyone with information is asked to call the incident room on 020 8358 0200 or Crimestoppers anonymously on 0800 555 111.