RTN? What did this? Pics Included

I have had the following coral for about a month now, and it has been doing fine. Last night I spent a good amount of time in my tank feeding things, and didn't notice anything wrong. Today after work I came home to the coral half destroyed. I am wondering if it maybe has something to do with the Toadstool that is relatively close to it... which has been closed for a few days (I think it may be shedding a layer of its skin? Or whatever it is they do). Any thoughts? Thanks guys.

 

could a nudibrach do this?

 

Unfortunately the likely hood of the RTN spreading is good and the frag is small.

I would move the leather, might make a difference.

Good luck.

 

Please post your parameters. They may shed so light.

 

any updates on this TPME06?

IMO - its always a good idea to keep SPS corals down flow or at a different height in the tank of any soft corals due to the possibility of chemical warfare
also running carbon is a good idea for the same reason

Steve