Unfortunately, in situations like this, the only person that can help is themselves. I am sure you did everything in your power, but some situations are too difficult for people to handle. I know it's extremely hard, but you can't blame yourself for this. Like you said, it is a part of the profession and it will probably happen again.
The only thing you can do is rely on your family and friends to be a support for you (as I am sure this has hit you very, very hard).