Police have arrested five people in Wembley after launching a murder inquiry following the fatal stabbing of a man in the early hours of Sunday morning.
Officers were called to a fight at 1.40am in Clarendon Gardens, Wembley, and found a 26-year-old man who had been knifed in the back.
He later died in Northwick Park Hospital.
His family have been informed but he has not been formally identified.
Four men and a 19-year-old woman have been arrested.
One, a 27-year-old, is at a north London hospital, suffering a stab wound to the back.
He is in a stable condition.
Neighbour Andrew De Metrious, 53, said: "I saw people running around outside, two or three guys had come out of the house. They looked like they were trying to call the police.
"There was a lot of commotion. A police car arrived and an ambulance and I saw them taking a stretcher. Usually we keep ourselves to ourselves because there have been a lot of people and families living there over the years.
"That house is bad luck. Lots of trouble has happened there. These people seemed quite quiet but it is a bit like a halfway-house. Peeople always seem to be coming and going.
"The lady across the road called up and told me the day before there had been fighting outside between a man and a woman. They were pushing each other and shouting.
"We have had our fair share of trouble on this road."
He said he thought the occupants were eastern European.
Another neighbour, who asked to be named only as Tamara, 28, said: "It is so strange to see the house all taped up. I have lived here for three years now and people have been moving in and out of that place. I think it has bad luck.
"There have been different landlords and the people in there before used to make lots of noise. These people came about a year and a half ago.
"They seemed ok. They were working people, they would get up and go to work. I can't believe this has happened on my doorstep. It is really scary."
Officers from the Homicide and Serious Crime Command are investigating.
Anyone with information is asked to call the Incident Room on 020 8358 0040 alternatively if you wish to remain anonymous please call 0800 555 111