What to do if the heir died without a will and how is it determined...?

In this case, inheritance will take place according to law.

In accordance with Part 2 of Art. 1258 of the Civil Code of Ukraine, each subsequent step receives the right to inherit in the absence of heirs of the previous step, their removal from the right to inherit, their refusal to accept the inheritance or refusal to accept it, except for cases of changing the order of obtaining the right to inherit.

Articles 1261-1265 of the Civil Code of Ukraine provide for FIVE stages of inheritance according to the law, which are called for inheritance in turn according to the procedure defined by the law. In the first place, the children of the testator have the right to inherit according to the law, including those conceived during the life of the testator and born after his death , the spouse who survived him, and his parents (Art. 1261 of the Civil Code). In the second place, the right to inherit by law belongs to the testator's own brothers and sisters, his grandmother and grandfather, both from the father's and from the mother's side (Art. 1262 of the Civil Code). In the third place, the right to inherit according to the law belongs to the uncle and aunt of the testator (Article 1263 of the Civil Code). In the fourth place, the right to inherit according to the law belongs to persons who lived with the testator in the same family for at least 5 years before at the time of the opening of the inheritance (Article 1264 of the Civil Code). In the fifth place, other relatives of the testator up to the sixth degree of consanguinity (cousin grandsons, great-nephews, great-grandfather and great-grandmother, etc.) inherit. At the same time, relatives of a closer degree of kinship exclude relatives of a more distant degree of kinship from the right of inheritance.