The question begging an answer is what happens to an inheritance where the testator in the will has not specifically provided for simultaneous death. It is worth mentioning that in our law, contrary to the English law, there is no presumption that the younger has survived the older. Without proof to the contrary, the presumption is that such persons died simultaneously (Ex parte Graham 1963 (4) SA 145 (D)).
Generally speaking, it is only beneficiaries who are alive at the date of death of the testator who are entitled to take benefits under a will. A beneficiary who predeceases or dies simultaneously with the testator acquires no rights, nor does his or her estate or heirs, unless the will provides to the contrary (see Ex parte Wessels and Venter NNO: In re Pyke‑Nott’s Insolvent Estate 1996 (2) SA 677 (O)). Where spouses who are each other’s heirs, be it under a will, or ab intestato, are killed in the same disaster – a shipwreck, an aeroplane crash, a motor accident – the fortuitous factor of survivorship may be crucial in determining the order of succession. Where one of the spouses has survived the other by as little as a few minutes, the survivor can succeed to the first‑dying but the first‑dying cannot succeed to the survivor. However, where both died at exactly the same moment neither can succeed the other.
Where the spouses died intestate and it cannot be established with certainty that one of the spouses survived the other, the courts will be inclined to assume that both spouses died simultaneously (see Corbett, Hofmeyr & Kahn, The Law of Succession in South Africa, Second edition, page 5). In this case the joint estate is administered and the balance for distribution must be divided into two. The respective half shares of the spouses will devolve on their separate intestate heirs. In practice the two estates are dealt with together, with only one account in the two estates.
Where the spouses died testate, the provisions in the Will of the spouses will determine how their separate estates will devolve.