How to cope with guilt over a dead kitten?

I have fostered many kittens so far and some do die no matter how hard you try and that's the hardest part. Recently I rescued four kittens from the street, their mother was run over by a car, and they were like one month old. They were staying with me, one died after a few days, one got adopted, one died after two months and the last one died 2 days ago. Somehow she sneaked out of the house and went to the road and ran over by a car. I tried my best to keep them safe but still felt responsible. I have seen a lot of death and a lot of success too but every death breaks me so much. She got adopted too and the family was supposed to come to pick her up today.

How to cope with guilt over a dead kitten?
Post Opinion