A 21-year-old man died after the motorcycle he was riding collided with an ambulance transporting patients.
The Mercedes ambulance was carrying two passengers when the crash happened, as it was joining Saxon Way in Andover, Hants, on Tuesday afternoon.
The rider of the blue Suzuki bike, a local man, suffered serious injuries and was taken to hospital in Basingstoke where he later died.
His passenger, aged 18, suffered serious, non life-threatening injuries.
The ambulance driver was taken to hospital with minor injuries but neither of his passengers - a 79-year-old woman and a 44-year-old man - was injured in the crash.
A police spokesman said: "The ambulance was conveying a patient to hospital following an emergency call.
"Police are investigating the circumstances of the incident and are appealing to anyone who saw the collision itself or either of the vehicles prior to it to get in touch."