Hampshire Police said a man in his 20s was arrested at the scene of the crash on suspicion of causing death by driving without due care and attention.
The double-crewed ambulance belonged to South Central Ambulance Service NHS Foundation Trust (SCAS) and was en route to Southampton General Hospital with the elderly patient.
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The family of the police officer who was murdered in the Westminster attack have thanked those who were with him 'in his last moments'.
Thousands of fans gathered for a public memorial honoring famous mother and daughter who died just a day apart.
More sunshine this Sunday