They don't have to convict the employees. However, all of them who are licensed should either lose their licenses or have them suspended. I take it you are neither a doctor nor a nurse. We have ethics. These people ignored their responsibility to their patients and allowed them to die.
There was a mandatory evacuation and the owners chose not to evacuate.
Not ALL doctors and not ALL nurses have ethics. The licensed staff should have stayed because the owners chose not to evacuate? They should have gone against mandatory evacuation orders?? Even if that meant NOT evacuating any minor children they may have? Should private citizens with children (or disabled/elderly) in their care be charged with neglect if they did not evacuate?
I think we have not heard enough of the facts in this case to make judgement.