The driver, a 42-year-old female ambulance technician, and the patient, an 88-year-old man, were pronounced dead at the scene.
A male crew member and a male relative of the patient remain in hospital both in a serious condition.
More top news
Monday night's weather for the west of the region
Monday night's weather for the east of the region
Michael Danaher, 50, has been sentenced to life in jail for murdering an antique book dealer - to steal a rare Wind in the Willows copy.