Leaving the car running and it moved and ran over a child

Q: I am a car driver. One day I stopped the car to relieve myself and left it running and forgot to take the necessary procedures to fix it. (Part No. 21; Page No. 412) As a result, the car slid backwards and killed an innocent boy who was behind it. What is the ruling in this case? Does this take the ruling of the involuntary manslaughter, which is stated in the Qur'an? If it takes the same ruling, I would like to explain to you my conditions.I am a poor man and sometimes can not provide the livelihood for my children. I am also suffering from kidney failure that weakens me badly, so I am not able to fast two consecutive months because of the pain of the disease that I patiently endure with good faith. Doctors advised me to break my fast due to the difficulty of the disease. In both cases, I cannot free one believing slave or fast. I am so confused on how to offer the Kaffarah (expiation) of my mistake. What should I do in this case? I hope you will give me a satisfactory answer that makes me comfortable and assures me about the acceptance of my repentance.

A: If the case is as you have mentioned, you must offer a Kaffarah of involuntary manslaughter because you caused the death of the child in question. Here the Kaffarah is freeing one believing slave; if there is no one available, you must fast two consecutive months. If you cannot afford both of them, the Kaffarah remains obligatory on you until you become able to offer any of them, since it is the right of Allah (Glorified and Exalted be He). If you fail to offer a Kaffarah during your lifetime, we hope that Allah will forgive you. (Part No. 21; Page No. 413) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.