As used in this subchapter:
(1) “Child” means a person under eighteen (18) years of age; and
(2) “Unexpected death” means: A death involving a child who has not been in the care of a licensed physician for treatment of an illness that is the cause of death;
(3) A clinical diagnosis of death due to Sudden Infant Death Syndrome; or
(4) A death due to an unknown cause.