Man found stabbed to death after car crash in west London
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Detectives do not believe the victim, who is in his 20s, was killed in a "road rage" attack but was in fact injured before the collision.
Ruth Holmstock, 72, whose flat overlooks the scene of the crash near West Ealing railway station, said she heard a single "thump".
"It was one of those 'oh f***' sort of crunches," she said. "The sort of noise you make when you reverse into a gate, but it was loud enough to make me go and see what it was.
"There were a lot of people hanging around. It looked like any other crash, like they were swapping insurance details."
Police were called shortly before 1.20am on Sunday and the victim was pronounced dead at the scene after he was found in a car suffering from a stab wound.
A picture of the scene appears to show a saloon car which has been hit by a Mini positioned sideways across Drayton Green Road.
Detectives believe the victim was injured before the collision.
Ms Holmstock said she saw five police cars, along with an ambulance and other medics' vehicles.
She said there was no sign of any injuries at first and police had removed someone from the car.
"I would never have dreamt that there was anyone injured," she continued.
"There was nothing to see. I was really surprised when the police got here.
"One minute the road was empty and the next minute they were doing CPR on someone."
Kiran Ramachandraiah, who lives in the same block of flats, said he woke up at about 2am to see medics trying to revive the victim.
"I couldn't see the person," he said. "He was completely surrounded by police and paramedics."
The victim has not been formally identified, but Scotland Yard said inquiries are under way to trace his family.
No arrests have been made and a post-mortem examination has not yet been carried out to determine the cause of death.