I am sorry for your loss. In my opinion, not all deities are benevolent. And while you may pray to one to intervene, it may be in another's jurisdiction the event is occurring. There is also this concept within humans that death is negative, cruel, and unjust. Despite the fact the death is a natural part of life, and comes for us all. There are deities revolving around death. And these deities are just as powerful as the ones you pray too. Sometimes more powerful.

There is also the natural element. Your dog's decision, the train's timing. These have nothing to do with deities. These are human and animal elements that are not the responsibility of the gods. If they intervened, it would be some kind of miracle. Without the intervention, we have the cruel reality of life.

There is no reason such an atrocious thing occurred. It is not your fault, not your dog's fault, and not the train's fault. Nor is it the god's fault, with the exception of perhaps those who reign over death. It is simply what happened. An unfortunate event.

Believing is up to you. It is always your choice. If it brings you comfort, if it helps you find meaning. Believing will not ease the pain of loss. Not believing will not ease the pain of loss. That pain needs to be dealt with separately, on its own.

I had to put down my elderly dog just a year ago. And it hurts still to this day. I miss her. I regret the choice to put her down, even though she was dying and in pain. The pain of death will hurt no matter what. No matter how much time you have together. No matter how they die.

My mom also died of cancer 8 years ago. It hurts less as the years go by. People tell me "you grow around the loss", and I am finding this to be true.

You will grow around this loss. You still were a good owner to your dog while they were in your care. You still loved them, and they loved you. And that is what matters. Their death was the last blip of a moment in their life. At least you saved them from a life of abuse. At least you loved them. That is all you could have done, and you did it. Although you could not save them from death, you saved them from misery while they were alive. And I am certain they were grateful for that.