So sorry to hear about this.  I once lost five fish and three shrimp over a twelve hour period for no apparent reason so I know where you are coming from.  It sounds like it is too far gone to save it now.  If you are looking at the skeleton I would guess that is all that is left of your plate coral. 
		
	
		
		
		
		
		
	
		
		
	
	
	 |