Catechism of the Council of Trent p. 179:

“On adults, however, the Church has not been accustomed to confer the Sacrament of Baptism at once, but has ordained that it be deferred for a certain time.  The delay is not attended with the same danger as in the case of infants, which we have already mentioned; should any unforeseen accident make it impossible for adults to be washed in the salutary waters, their intention and determination to receive Baptism and their repentance for past sins, will avail them to grace and righteousness.”

VS.

St. Augustine: “If you wish to be a Catholic, do not venture to believe, to say, or to teach that ‘they whom the Lord has predestinated for baptism can be snatched away from his predestination, or die before that has been accomplished in them which the Almighty has predestined.’ There is in such a dogma more power than I can tell assigned to chances in opposition to the power of God, by the occurrence of which casualties that which He has predestinated is not permitted to come to pass. It is hardly necessary to spend time or earnest words in cautioning the man who takes up with this error against the absolute vortex of confusion into which it will absorb him, when I shall sufficiently meet the case if I briefly warn the prudent man who is ready to receive correction against the threatening mischief.” (On the Soul and Its Origin 3, 13)

Can someone die by accident before God has accomplished what he has preordained?

St Augustine's position on this is hardly definitive.

It is definitive for St. Augustine, what I posted was his final position on the catechumen. Besides, no one can argue against it. They whom the Lord has predestinated for baptism can't be snatched away from his predestination, or die before that has been accomplished in them

There is ample theological support for the position that catachumens are saved,

I would not call it ample, you'll find that the Fathers were against the idea. Besides, the question is, can someone die before God accomplishes what he has preordained, can "fate" trump God's plan?

No one can say someone is not Catholic or is heretical for having the position that catachumens can be saved.

That is correct. However, it is a rare thing today to find a Catholic that limits BOD to the catechumen.

Can someone die by accident before God has accomplished what he has preordained?

There are thousands of examples of people being raised from the dead just to be baptized. Yet there has never been one example of a person saved by baptism of desire. Why would God SEND BACK thousands to be baptized if baptism of desire were salvific?

From : Peter Claver: Saint of the Slaves, by Fr. Angel Valltiera, S.J., Burns and Oates, London, 1960, pp. 221,222.:

"The affair of the slave Augustina, who served in the house of Captain Vincente de Villalobos, was one of the strangest in the life of Claver...When Augustina was in her last agony Villalobos went in search of Claver. When the latter arrived the body was already being prepared for the shroud and he found it cold to the touch. His expression suddenly changed and he amazed everyone by crying aloud, "Augustina, Augustina." He sprinkled her with holy water, he knelt by her, and prayed for an hour. Suddenly the supposedly dead woman began to move...All fell on their knees. Augustina stared at Claver, and as if awakening from a deep sleep said, "Jesus, Jesus, how tired I am!" Claver told her to pray with all her heart and repent her sins, but those standing by, moved by curiosity, begged him to ask her where she came from. He did so, and she said these words: "I am come from journeying along a long road. It was a beautiful road, and after I had gone a long way down it I met a white man of great beauty who stood before me and said, 'Stop, you cannot go further.' I asked him what I should do, and he replied, 'Go back the way you have come, to the house you have left.' This I have done, but I cannot tell how." On hearing this Claver told them all to leave the room and leave him alone with her because he wished to hear her confession. He prepared her and told her that complete confession of her sins was of immense importance if she wanted to enter that paradise of which she had had a glimpse. She obeyed him, and as he heard her confession it became clear to Claver that she was not baptized. He straightway ordered water to be brought, and a candle and a crucifix. Her owners answered that they had had Augustina in their house for twenty years and that she behaved in all things like themselves. She had gone to confession, to Mass, and performed all her Christian duties, and therefore she did not need Baptism, nor could she receive it. But Claver was certain that they were wrong and insisted, baptizing her in the presence of all, to the great delight of her soul and his, for a few minutes after she had received the sacraments she died in the presence of the whole family."  

22 Peter Claver: Saint of the Slaves, Fr. Angel Valltiera, S.J., Burns and Oates, London, 1960, pp. 221,222.

it is a rare thing today to find a Catholic that limits BOD to the catechumen.

How true. BOD is for everyone who did not receive a proper baptism. As it is understood and taught by many Catholics today, BOD actually renders the Sacrament of Baptism superfluous. Besides, who wants to be the one to tell grieving parents that their little baby is not with God in heaven? It is so much easier to just tickle their ears.

Catechism of the Council of Trent p. 179:

“On adults, however, the Church has not been accustomed to confer the Sacrament of Baptism at once, but has ordained that it be deferred for a certain time.  The delay is not attended with the same danger as in the case of infants, which we have already mentioned; should any unforeseen accident make it impossible for adults to be washed in the salutary waters, their intention and determination to receive Baptism and their repentance for past sins, will avail them to grace and righteousness.”

If the Council of Trent said it, then that's the end of the matter. Church Councils are infallible. St. Augustine (as much as I love him) isn't.

I understand what you are saying, Nadie, and I agree with you that there is no question of God's will being thwarted by fate. That much is certain. It seems that St. Augustine, in the quoted passage, was chiefly concerned to settle that very point, and the involvement of BOD in the matter is largely accidental. The statement

1. No one whom God predestines [for Baptism] can be snached away [from baptism].

is true only because the more general statement

2. No one whom God predestines [for X] can be snatched away [from X].

is true by definition. Using 'baptism' as an instance of 'X' neither adds nor subtracts any from the truth-value of the general statement. The BOD controversy is created by a separate question, viz. whether only those who have completed water-baptism may be saved. We know that this question is answered in the negative, since we are witness to several counterexamples in the following. Neither St. Dismas, nor any of the Old Testament Patriarchs, nor any of the Holy Innocents, were ever baptised with water. They were admitted into Heaven solely by divine fiat, but God has the power to do such things if He wants to. In these cases we say that they were "baptized" in their blood, or by their desire to be united to Christ. Note the presence of the scare-quotes in the previous sentence. The terms 'baptism of blood' and 'baptism of desire' are very unfortunate and probably ought to be dropped, since they merely confuse people and often lead to the very abuses you've listed above. However, the ideas of a martyrdom in lieu of water-baptism, or a spiritual union with Christ in lieu of water-baptism, being sufficient for salvation in certain circuмscribed cases, are not impossible ideas.

The BOD controversy is created by a separate question, viz. whether only those who have completed water-baptism may be saved.  

PereJoseph correctly answered your examples.

Let me add that there would be no need for speculations on all the variations of "baptism of desire", if there was no need for baptism of water.

It is a dogma of the Church that to be a member of the Church one must be baptized. It is also a dogma of the Church that those who die outside of the Church are lost.

The dogmatically defined language could not be any clearer. If it does not mean what it says, then nothing of Church teaching is clear.

Pope Pius XII, Mystici Corporis (# 22), June 29, 1943: “Actually only those are to
be numbered among the members of the Church who have received the laver
of regeneration [water baptism] and profess the true faith.”

Pope Pius XII, Mystici Corporis (# 27), June 29, 1943: “He (Christ) also determined that through Baptism (cf. Jn. 3:5) those who should believe would be
incorporated in the Body of the Church.”

Pope Pius XII, Mediator Dei (# 43), Nov. 20, 1947: “In the same way, actually that baptism is the distinctive mark of all Christians, and serves to differentiate
them from those who have not been cleansed in this purifying stream and
consequently are not members of Christ, the sacrament of holy orders sets the
priest apart from the rest of the faithful who have not received this
consecration.”


Council of Trent. Seventh Session. March, 1547. Decree on the Sacraments.
On Baptism

Canon 5. If any one saith, that baptism is optional, that is, not necessary unto salvation; let him be anathema.

This Canon is on the sacrament of baptism, that is the subject and title of the  Session. It is very clear that the sacrament of baptism is necessary for salvation. BOD is not a sacrament!

--------------------------

CANON 2.-If any one saith, that true and natural water is not of necessity for baptism, and, on that account, wrests, to some sort of metaphor, those words of our Lord Jesus Christ; Unless a man be born again of water and the Holy Ghost; let him be anathema.

This is very clear too, and concurs with the Canon 5 above.
---------------------------------------
Session VII (March 3, 1547)
Canons on the Sacraments in General

Canon IV. If any one saith, that the sacraments of the New Law are not necessary unto salvation, but superfluous; and that, without them, or without the desire thereof, men obtain of God, through faith alone, the grace of justification; though all (the sacraments) are not indeed necessary for every individual; let him be anathema.

(The heading of this Session is sacraments in General. That means all seven sacraments, baptism, confirmation, penance, communion, matrimony, extreme unction, and the priesthood. Baptism of desire is not a sacrament, so please refrain from salivating at the sight of the word “desire”. One can’t become a priest or be married “by desire”.)

This says that the sacraments are necessary for salvation. It also says that not all are necessary for every individual, therefore, at least one is necessary for salvation. this one can only be the sacrament of baptism, since that's exactly what the two Canons on the sacrament of baptism say.

The three canons concur with each other perfectly and clearly.
---------------------------------------------------------
Now, the proponents of BOD of the catechumen, ask the speculative question:

What happens to a catechumen:
1)who is sanctified by God before being baptized,
2)then dies unexpectedly,
3)while still in a state of grace,
4)without anyone around to baptize him?

This is total speculation. What are the chances of such a possibility? Here's additional comments concerning points 1,2,3, and 4 above:

1) Yes, a person potentially can be sanctified before receiving the sacrament of baptism, Trent has said so, however, how long before baptism? It maybe one second before the water hits his head. If a person is sanctified one second before baptism, that would be before.

2)3)4)- no one dies unexpectedly to God. Why would God sanctify someone, then take his life before anyone can baptize him?


The only answer to the speculative question above, that would fulfill all the requirements of Trent touched on by this question, is that, every person sanctified before receiving the sacrament of baptism, will be baptized. They cannot die unbaptized, God would not allow them to die. No such person has ever existed or will ever exist. This is what St. Augustine meant by:

St. Augustine: “If you wish to be a Catholic, do not venture to believe, to say, or to teach that ‘they whom the Lord has predestinated for baptism can be snatched away from his predestination, or die before that has been accomplished in them which the Almighty has predestined.’ There is in such a dogma more power than I can tell assigned to chances in opposition to the power of God, by the occurrence of which casualties that which He has predestinated is not permitted to come to pass. It is hardly necessary to spend time or earnest words in cautioning the man who takes up with this error against the absolute vortex of confusion into which it will absorb him, when I shall sufficiently meet the case if I briefly warn the prudent man who is ready to receive correction against the threatening mischief.” (On the Soul and Its Origin 3, 13)

And the rest of what you wrote is simply prescinding from the argument

Your NEW argument is that the sacrament baptism is not necesary for salvation. You said:The BOD controversy is created by a separate question, viz. whether only those who have completed water-baptism may be saved.

Therefore, it is you who has changed the subject, therefore, I answered your objection.