I can find no Catholic teaching that a tragic death under different circumstances imparts Baptismal Grace.
It is an open question. However, certain magisterial teachings, considered together, seem to imply that they must be saved, especially in the case of the prenatal who dies in the womb (no opportunity for water baptism).
God wills all persons to be saved:
Cardinal Ratzinger: “It must therefore be firmly believed as a truth of Catholic faith that the universal salvific will of the One and Triune God is offered and accomplished once for all in the mystery of the incarnation, death, and resurrection of the Son of God.” [Dominus Jesus, n. 13-14]
Pope Saint John Paul II: “The universality of salvation means that it is granted not only to those who explicitly believe in Christ and have entered the Church. Since salvation is offered to all, it must be made concretely available to all.” [Redemptoris Missio, n. 10]
Therefore, salvation must be concretely available even to prenatals who die in the womb. The saying that they would have been saved, if they had been born and been baptized, is not concrete availability. The idea that these little souls go to limbo is not salvation. The Church teaches that salvation in Christ is fulfilled in Heaven.
Pope Benedict XVI: “Human beings cannot completely fulfill themselves, they cannot be truly happy without God.” [Homily, Sunday, 24 May 2009]
Pope John Paul II: “Without God, man cannot fully find himself, nor can he find his true happiness.” [Homily, 9 November 1999]
Only persons who commit a mortal sin can possibly be condemned to Hell:
“God predestines no one to go to hell; for this, a willful turning away from God (a mortal sin) is necessary, and persistence in it until the end.” [CCC 1037]
“Because God knows, searches and clearly understands the minds, hearts, thoughts, and nature of all, his supreme kindness and clemency do not permit anyone at all who is not guilty of deliberate sin to suffer eternal punishments.” [Quanto Conficiamur Moerore, n. 7.]
The above quotes seem to contradict the teaching that persons who die in a state of “original sin alone” are sent to Hell. But the conflict can be resolved: a person commits a mortal sin of omission if they fail to find sanctifying grace, by some form of baptism in their life despite ample opportunity. Only someone who has ample opportunity for some form of baptism can possibly die in a culpable state of original sin alone. Prenatals, infants, and little children do not have ample opportunity.
In summary, the Church teaches that:
- God offers salvation to all human persons.
- This salvation is concretely available to all.
- Only persons who commit deliberate personal sin, specifically actual mortal sin, and who die unrepentant are punished in Hell.
- No human person can be happy without grace and without God.
- Prenatals and infants cannot commit any sin deserving of Hell.
Therefore, prenatals who die in the womb, for whom formal baptism with water is unavailable, must receive some type of non-formal baptism (of desire or blood) prior to death. Otherwise, the salvific will of God would not be universal, since it would exclude many billions of human persons.