Is there any transparency in healthcare?

I don't have anyone to talk to about this, so I'm writing about it here.

I vaguely remember my aunt (चाची) making me food and proudly talking about me to anyone out there. She was a selfless human who has always lived her life for family.

My aunt (चाची) passed away who was in her early 50s. Before her demise, she had kidney stone surgery at Agra followed by an unknown complication on the night of discharge. When my family took my aunt to the hospital at night, we were asked to take her somewhere else since the doctor who performed the surgery was not available and any other doctor at the hospital didn't want to touch her. We rushed to Delhi in the early morning but on arrival, the attending doctor declared that there is no life in her anymore.

This incident has left us in complete shock. How can a person in her 50s with no history of ongoing disease or condition lose her life after a routine surgery by an experienced doctor?

Her two children & husband are left behind with no answers to how this happened.

We are clueless on how we can find out what exactly happened. Can anyone help?

May she rest in peace!