A man is in a serious condition after an ambulance that was transporting him to the Royal Adelaide Hospital rolled onto its side after a collision with a car on Tuesday night. Police said the ambulance was also carrying a passenger and two paramedics when it collided with a Toyota Camry just outside the hospital, at the intersection of Port Road and North Terrace in the Adelaide CBD at about 10:45pm. The patient and passenger being transported to the hospital were subsequently taken to the Royal Adelaide Hospital for treatment. Police said paramedics and the driver of the Camry were not seriously injured in the crash, and the driver was treated at the scene for minor injuries. The male patient remains in a serious condition at the hospital.