NUM400 A person must be careful that his actions do not lead to someone's death. The Torah states that if someone kills another person unintentionally, he is obliged to flee to one of the six cities of refuge in Eretz Yisroel which were especially set aside for this purpose. The Chinuch (410) explains that this punishment, going into exile, can be equated with death. The manslayer, albeit his action was not intentional, has to atone for his negligence which caused the loss of someone's life. A person must be very careful while engaging in any action that could possibly harm someone. Today this is especially relevant when driving a car. A driver must devote himself entirely to driving since one careless move could easily lead to a fatal accident. When you are upset or tired, do not drive.