Taken from the book "Purgatory Explained" by Fr. Schouppe, S.J. - Part II,
Chapter XXXIII (TAN Books).

Father Ravignan, an illustrious and holy preacher of the Society of Jesus,
also cherished great hope for the welfare of sinners carried away by a
sudden death, when otherwise they had borne no hatred in the heart for the
things of God. He lived to speak of the supreme moment, and it seems to
have been his opinion that many sinners are converted in their last
moments, and are reconciled to God without being able to give any exterior
sign thereof. In certain deaths there are mysteries of Mercy where the eye
of man sees nothing but strokes of Justice. As a last glimmer of light, God
sometimes reveals Himself to those souls whose greatest misfortune has been
to ignore Him ; and the last sigh, understood by Him who penetrates hearts,
may be a groan that calls for pardon ; that is to say, an act of perfect
contrition. General Exelmans, a relative of this good father, was suddenly
carried to the tomb by an accident, and unfortunately he had not been
faithful in the practice of his religion. He had promised that he would one
day make his confession, but had not had the opportunity to do so. Father
Ravignan, who, for a long time had prayed and procured prayers for him, was
filled with consternation when he heard of such a death. The same day, a
person accustomed to receive supernatural communications thought he heard
an interior voice, which said to him, "Who then knows the extent of God's
mercy? Who knows the depth of the ocean, or how much water is contained
therein? Much will be forgiven to those who have sinned through ignorance."