Two cars collided and three people died. What does he have to do?
Question

                What is the ruling on someone who had a traffic accident and three people died in the car that hit him, and the accident was not deliberate on the part of either driver?.
Praise be to Allah.
    Traffic accidents should be referred to the experts in that 
    field and eyewitnesses who saw what happened; this brief description is not 
    enough. 

    If the experts rule that one of the two parties was negligent 
    or aggressive, such as if he drove in the opposite direction or he cut off 
    the other driver, or he was careless in changing tires which led to his car 
    turning over and hitting the other car, then he is the negligible party and 
    is liable for the deaths of others and the destruction of property. There 
    may have been negligence on both sides, in which case each party is liable 
    for damage caused to the other, whether that be damage caused to people or 
    property, to the extent to which they were negligent. 

    The Islamic Fiqh Council issued a statement on traffic 
    accidents in which it says: 

    Accidents involving vehicles are subject to the Islamic 
    shar’i rulings on criminal acts, even though they are usually caused by 
    errors. The driver is responsible for damage caused to the other person, 
    whether that is physical harm suffered by him or damage to his property. 
    After deciding who is at fault and the extent of damage caused, he is not to 
    be absolved of blame except in the following cases: 

    1 – If the accident happened as the result of something 
    beyond his control and he could not avoid it.

    2 – If the damage is caused primarily by the one to whom the 
    damage is done.

    3 – If the accident resulted from negligence or aggression on 
    the part of another, and the other is to be deemed responsible. 

    And they said: If the driver and the injured party both 
    caused the accident, then each of them is liable for physical damage or 
    damage to property caused to the other. 

    Shaykh Ibn Baaz (may Allaah have mercy on him) was asked: 
    There was an accident in which two cars crashed into one another. In one car 
    there were two people, one of whom died. According to the police, the driver 
    of the first car was 30% responsible, and the driver of the other car was 
    70% responsible. With regard to the kafaarah (expiation), should the driver 
    of the first car fast for two consecutive months or for a time proportionate 
    to the degree to which he is to blame, as is the case with diyah (blood 
    money)? 
He replied: If two or 
    more people are jointly responsible for killing someone by mistake, then 
    each of them has to offer expiation independently, because expiations cannot 
    be split between individuals, as the scholars have stated, 

    Fataawa Islamiyyah, 3/360 

    The Shaykh was also asked: 

    When my father was driving a car, he crashed into another car 
    and the driver of the other car died, may Allaah have mercy on him. The 
    police confirmed that the accident was entirely the fault of the deceased 
    and the family of the deceased agreed to forgo the diyah (blood money), may 
    Allaah reward them with good. My question now is: Does my father have to 
    offer the expiation of fasting for two consecutive months or not? 

    He replied: If the situation is as you describe then your 
    father does not have to offer any expiation because he is not to blame and 
    he cannot be described as a killer. 

    Fataawa Islamiyyah, 3/356. 
The point of quoting 
    these fatwas is so that you may know the importance of following the rulings 
    of the experts and eyewitnesses and finding out the details so that it may 
    be determined who is to blame and to what degree. 

    The fact that the accident was not caused by a deliberate 
    action does not mean that the blood money or expiation can be waived. 
And Allaah knows 
    best.