Japanese 使役｛しえき} and 使役{しえき}受身{うけみ} grammar

Question

その映画から、事故で子供を死なせてしまった母親の悲しさが伝わってきた。

from this sentence,

Translation: conveyed the sadness of the mothers of the children who killed in accident

or

conveyed the sadness of the children whom mother was killed in accident

and also I don't understand why they used shieki and not shieki ukemi.

Besides that also the particle を is really confusing, who is the subject and also the object in this sentence 「じこでこどもをしなせてしまった」 ?

Could you explain to me?

Answer 1

“その映画から、事故で子供を死なせてしまった母親の悲しさが伝わってきた” can be translated as;

The movie conveyed heartrending sorrow of the mother who lost her child by an (a traffic) accident. The sadness (sorrow) is clearly that of mother, not the child.

The verbatim translation of “事故で子供を死なせてしまった母親” is “the mother who made her child die / killed,” but it doesn’t mean the mother killed the child, and no mother under the sun "allows" and "permits" somebody to kill her child. The accident killed the child.

It’s better to interpret ”子供を死なせてしまった母親” as “the mother who lost her child” than “the mother who made her child be killed.”

The subject in the sentence is “母親の悲しみ - the sorrow of mother,” which is followed by the verb, “伝わってきた – was conveyed.”

Answer 2

「子供を死なせる」 means to "allow", or "cause" the death of this child.

So 「事故で子供を死なせてしまった母親」 would mean something like:

the mother who caused (her) child's death in an accident

The mother is the subject. The child is the object. The mother is the one who causes the child's death.

If you put the 使役{しえき} of 「死ぬ」 into 受身｛うけみ｝ it would look like this:

死なせる　⇒　死なせられる

「事故で子供を死なせられてしまった母親」

It's kind of hard to imagine what this would mean though. Maybe someone else (not the mother) would have caused the child's death? But that's probably a bit of a stretch.