Wow. I just don't know. I mean I always say where there's green there's hope. But that does look pretty bad. I wonder why that one has failed where the other 2 did not? Its hard for me to tell anything about the crown from the pics. If the fronds are all dying off it seems to indicate something wrong with the root system. Maybe trench around it and see if you can see anything wrong with the roots? It may be a goner.
