A 75-year-old woman has died after an ambulance taking her to hospital crashed in Lincolnshire.
Lincolnshire Police said the patient was pronounced dead at the scene after the ambulance left the A16 at Sibsey, near Boston, at 2.58am.
Two ambulance service staff, men aged 52 and 62, were taken to Boston's Pilgrim Hospital and treated for minor injuries.
In a statement, East Midlands Ambulance Service said: "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."
East Midlands Ambulance Service chief executive Phil Milligan said: "We offer our sincere condolences to the family and friends of the patient who died following this tragic incident."
A Lincolnshire Police spokesman confirmed the ambulance had left the road and ended up in a ditch off the A16.
He said no arrests had been made and officers are still investigating the incident.
No details have been released about the patient or the reason for her being taken to hospital.