Answer:
Unfortunate Accident
Step-by-step explanation:
Since the accident was not due to any lack in the driving skills, but as Carla could not function properly, because of Heart Attack, this is not an accident for which Carla could be held liable.
Although Carla was driving, but she could be held liable, as that is because of unfortunate circumstances, not in the hands of Carla, and could not be avoided by the actions of Carla.
Thus, it is termed as Unfortunate Accident.