A person who, if the person survived a decedent by 120 hours, would be the decedent's heir is considered not to have survived the decedent for the required period if:
(1) the time of death of the decedent or of the person, or the times of death of both, cannot be determined; and
(2) the person's survival for the required period after the decedent's death cannot be established.
Official text of the Texas Estates Code as published by the Texas Legislative Council.