President Kaczynski of Poland died with, among others, his wife in the Smolensk air accident. Death of spouses simultaneously is called Commorientes.

If they had been Irish, probably they would have owned their residence in joint names (in joint tenancy). The effect of this form of ownership is to vest full ownership in the survivor. Significantly, the property never becomes part of the estate of the first partner to die. However, commorientes defeats this process. Which died first?

Under Section 5 of the Succession Act 1965 simultaneous death is presumed in some circumstances.

Under Section 68 of the Civil Law (Miscellaneous Provisions) Act 2008 a joint tenancy in commorientes is converted into a tenancy in common in equal shares and each share forms part of the estate of the deceased partner.