Is expiation, by fasting or charity, obligatory for one whose wife died in a car rollover accident while he was driving?

If you did not cause the accident due to negligent driving or car maintenance, then there is nothing upon you. However, if the accident was due to your negligence, then you are liable for the expiation of accidental killing: freeing a believing slave. If you cannot find one, then fasting for two consecutive months, as Allah the Almighty says: (And it is not for a believer to kill a believer except by mistake. And whoever kills a believer by mistake - then the freeing of a believing slave and a compensation payment presented to his family [is to be made] unless they give [up their right as] charity... And he who does not find [one or afford it] - then a fast for two consecutive months as repentance to Allah. And ever is Allah Knowing and Wise). Feeding [the poor] is not sufficient in this case.