Does the Catholic Church have a contingency plan for the case that the pope and all cardinals are dead?

Question

Most modern democratic countries have a chain of command which can be triggered in case of disastrous events and is intended to ensure the continuity of the functioning of the country.

This chain of command also relies on the fact that there is a plan to get back to normality. This usually means that the person in command has a set of elections to call (at a gouvernemental level) or people are automatically promoted to the missing positions (army, companies, ...).

How would that work with the Catholic Church?

Let's imagine a case that during papal election all the electors (cardinals) die (accident, terrorist attack, ...). Let's also imagine that all of the cardinals are present (which is very likely).

Is there a plan for such situation?

I am curious about that fact because in a democratic country the solution are popular elections (which bring in new rulers), in other institutions people would be automatically promoted to the new functions promotion. In contrast, the Catholic Church only has a handful of electors (compared to the whole Church) and cardinals are explicitly nominated by the Pope (and nobody else).

Answer 1

The Catholic church cannot be treated a "normal" state. The Pope is believed not to be chosen by Cardinals, but called by God, who divinely inspires the selection of the Pope. There would be a lot of prayer. Divine guidance would be sought. But then the Bishops would decide how to proceed. The meeting of bishops is called an ecumenical council. While the Pope has great authority in the Church, the highest level of Authority (below God) is the ecumenical council of bishops.

The council doesn't need to be summoned by a Pope to be valid, all the early councils were summoned by the Roman Emperor. If the bishops are gathered they have complete (and infallible) authority to decide on any aspect of church doctrine, law or procedure. An ecumenical council could be invited to form (by anyone, the remaining bishops could send out the invitations), and that council could either choose a pope, or choose cardinals to form a new conclave.

As with many of these apocalyptic questions, you are assuming that the rules, traditions and processes that have been designed to work in normal times, would be applied in the most extraordinary.

Answer 2

The rules for electing a new pope are given by the apostolic constitution, Universi Dominici gregis

On a quick read through, I can find no evidence that there is any plan for the event that the pope, and all 122 cardinal electors are killed more or less simultaneously. However, generally one divides the church into bishops, priests, and laity (in a sense the pope, cardinals and archbishops are just higher ranking bishops, all entrusted with the leadership of the church). And although Universi Dominici gregis itself forbids it, one could imagine that in extraordinary circumstances the Synod of Bishops would step up to the role of nominating a new body of electors.

It happens from time to time that countries hold some sort of constitutional convention to rewrite the rules. Often for less worthy reasons than you hypothesise. There is precedent for this sort of thing, for example the Council of Constance

Once a few generations have gone by, there might be a minority of people holding the (doubtless deemed heretical) belief that the papal line has ended. Generally, one would expect that the vast majority of Catholics would accept the new situation, especially if the new pope or one of successors retrospectively endorsed it.