The East Anglian Air Ambulance was called to an address in Great Cambourne shortly before 8.20am. The helicopter landed four minutes later but the boy had died by the time they got to the scene. A spokesman for the air ambulance said: We were called at 8.19 to reports of a five-year-old boy suffering a cardiac arrest in Cambourne. The pilot got there swiftly but unfortunately, when we arrived the boy was already deceased. A police spokesman said: We were called by the ambulance service at 8.20am today to reports of the death of a child at a property in Great Cambourne. We are treating the death as unexplained. A post mortem will be carried out early next week to determine the cause of death. A spokesman for the East of England Ambulance Service said: We attended an incident in Cambourne today at 8.13am to reports of a child who was unconscious and not breathing. He was declared deceased on arrival and we took him to Addenbrookes.