A shopper died after having a cardiac arrest at a convenience store in Isleworth.
The man, reported by police to be in his 60s, collapsed at Londis, in St Johns Road, on Wednesday (April 22), shortly before 10pm.
Paramedics tended to him at the scene, close to Isleworth station, before taking him to West Middlesex Hospital, where he died that evening.
Store manager Juren Jagamohan said the man was a regular customer who lived locally and had been coming to the store for about five years.
"I was serving another customer when he collapsed inside the store. I rushed round to help him before calling for an ambulance," he said. "I didn't know his name but he told me once that he worked as a security guard at Kew Gardens.
"It's very sad."
A London Ambulance Service spokeswoman said paramedics were called at 9.50pm and treated a man who was suffering a cardiac arrest.
She said he was taken to hospital as a priority.
A police spokesman said a man, reported to be in his 60s, was taken to hospital where he died that evening.
He said the man's death was not being treated as suspicious.