Coroners must investigate all deaths which are sudden, unnatural, violent, or of unknown cause. This can include deaths of newborn babies such as in the tragic case of Clara Tully. Coroners cannot by law investigate cases in which a child has not lived independently of its mother, such as stillbirths. They can, however, open an investigation if there is any doubt over whether there was independent life, once they have received a report of the case. There are also hospital and medical investigations into stillbirths.