What constitutes a wrongful death?

I am so sorry for your loss.  Wrongful death, by definition, occurs when a person is killed due to the negligence or misconduct of another individual, company or entity. An action for wrongful death belongs to the decedent's immediate family members (often called "distributees").  In this situation it is hard to know if what happened was negligence.  The storm was an act of God but the inadequate back up may have been.  It needs to be investigated.  You should speak with an attorney who specializes in this matter as soon as you can.  I am wondering if there was a health care proxy and any indication that she did not want to be kept alive artificially as well.  Seek help.