Is one expiation required of a killer by mistake for all those killed, or an expiation for each soul killed, and if he is unable to fast, is another expiation sufficient for him?

Whoever kills several people by mistake, their blood money is incumbent upon his 'aqilah (male relatives on the paternal side), and an expiation is incumbent upon him for each soul. If he is temporarily unable to fast, there is nothing upon him until the inability ceases. If he is permanently unable, he transitions to feeding (the poor).