Is the death of one's child due to sins and transgressions committed by the parent considered unintentional killing, and is expiation obligatory upon him after his repentance and remorse?

What afflicts people in terms of calamities and adversities is due to their sins and shortcomings, as stated in the Almighty's قول (statement): "And whatever calamity befalls you, it is because of what your hands have earned, and He pardons much." (Quran 42:30) This does not mean that whoever commits a sin and then their child dies is considered their murderer, for intentional or accidental killing has its own specific definition. A sin may be a cause for a worldly punishment to alert the disobedient and remind them of Allah's power, and the calamity may be a cause for repentance and the raising of ranks. If the disobedient repents with sincere repentance, Allah accepts their repentance and replaces their evil deeds with good ones, as stated in the Almighty's قول (statement): "Except for those who repent and believe and do righteous deeds; for them Allah will change their evil deeds into good ones. And Allah is ever Forgiving, Merciful." (Quran 25:70)