A 75-year-old woman from Lincolnshire has died after the ambulance she was travelling in crashed near Sibsey in the early hours of the morning.
The pensioner, who has not been named, was pronounced dead at the scene just after 3.00am.
The crash happened on the A16 Boston Road at Sibsey when the vehicle left the road near the junction with the B1184 High Ferry Lane.
Lincolnshire Police said: "The two ambulance service staff, a 62-year-old man and a 52-year-old man, were taken to Boston Pilgrim Hospital and treated for minor injuries.
"A 75-year-old woman, who was a patient travelling in the ambulance, was pronounced dead at the scene."
Police are now appealing for any witnesses who may have information about the crash.
The East Midlands Ambulance Service said in a statement: "One of our double-crewed ambulances was involved in a road traffic collision just before 3am this morning on the A16 Boston Road, Lincolnshire.
"The vehicle contained two of our ambulance crew and a patient who was being taken to hospital. No other vehicle was involved.
"The incident is subject to a police investigation and therefore it is not appropriate for us to make further comment at this time."