So its good that the infant dies because it will be instantly transported to a better place. What, then does the infant gain during its time here? Is it not evil for god to bring a child into the world only to drown in a tsunami? Why couldn't god have just birthed the child directly into heaven? What loving person could look at the choice between birthing a child directly into heaven and birthing it on earth only to be drowned a few days later and choose the latter? The baby isn't cognitively developed enough to form memories or become self aware, so it brought no benefit to the baby. The baby is, however developed enough to fell pain, and I might remind you that a drowning death is tremendously painful - so much so that merely simulating it is considered a form of torture.
So, let me rephrase the question, what is gained by good allowing a baby to be tortured to death?