Are blood money and expiation obligatory for someone whose car overturned and his son-in-law's daughter died, knowing that he was driving at a moderate speed and was not the cause of the malfunction that led to the accident?

The driver is liable for blood money (Diyah) and expiation (Kaffarah) if the accident was due to their transgression or negligence, such as overloading the vehicle, excessive speed, or neglecting to repair defects in the car.

However, if there was no transgression or negligence on the part of the driver, for example, if a tire burst due to divine decree without any fault of theirs, or if they swerved the car to avoid an anticipated danger, then they are not liable for any blood money or expiation.

The fundamental principle is the driver's innocence, and blood money and expiation are not obligatory upon them unless it is proven that they caused the accident through transgression or negligence.