From "Donald Trump’s niece reveals in new book that she leaked details of his 'fraudulent' tax schemes, alleges he contributed to his brother’s death and says his retired federal judge sister disapproves of him" (Daily Mail).
The niece is the daughter of the brother who died. It's sad to think about what could have been done to prevent a death — sad to look for living persons to blame.
Most of the time, we soothe the survivors and tell them there's nothing they could have done, and when we choose to say, no, there are things you could have done that you did not do, it is probably not because those things were more obvious or had more potential to help.