Short answer. It depends on why the question is being asked. For most purposes Rule 131, Section 3 settles survivorship by rules based on age and sex. But for succession the section takes the opposite approach: whoever alleges one died first must prove it, and failing proof they are treated as dying together.
What the law says
the survivorship is determined from the probabilities resulting from the strength and the age of the sexes
Rule 131, Section 3 — Disputable presumptions. Read the full provision →
What the law says
whoever alleges the death of one prior to the other, shall prove the same; in the absence of proof, they shall be considered to have died at the same time
Rule 131, Section 3 — Disputable presumptions. Read the full provision →
Why the order of death matters at all
When people die in the same disaster, the sequence can decide who inherits what. If a parent died first, the child inherits and then passes that inheritance on through their own estate; if the child died first, the property never moves that way at all. Insurance entitlements and rights that pass only to a survivor turn on the same point. Since a wreck, a fire or a collision rarely leaves anyone able to say who died first, the law has to supply an answer — and Section 3 supplies two different ones.
The general rule: fixed survivorship rules
For purposes other than succession, where two persons perish in the same calamity such as a wreck, battle or conflagration, and it is not shown who died first and no particular circumstance allows the inference to be drawn, the survivorship is determined from the probabilities resulting from the strength and the age of the sexes. The section then sets out a fixed scheme worked out by age brackets — under fifteen, over sixty, and the range between — with a stated result for each combination. It applies only when the evidence is genuinely silent.
Succession is carved out and reversed
The general rule opens with the words except for purposes of succession, and the section closes with a separate clause for that case. Where two or more persons are called to succeed each other and it is doubtful who died first, whoever alleges the death of one prior to the other, shall prove the same; in the absence of proof, they shall be considered to have died at the same time. There is no age-and-sex scheme here. The burden falls on whoever asserts a sequence, and if nobody can prove one, neither inherits from the other.
Evidence beats every presumption here
Both limbs are last resorts, and both give way to actual proof. Medical findings, rescue and recovery records, timestamps, and the accounts of survivors can establish a sequence directly, and where they do the presumptions never come into play. That is worth knowing before an estate is settled on the assumption that a rule of thumb governs: in a succession dispute especially, evidence of the order of death is what decides the case, and the presumption of simultaneous death is only what remains when there is none.