Yellowhead Jawfish.... Victim of cave in??

[X-Treme]

So I've had this yellowhead jawfish for about a year and a half.....ALWAYS bobbing up and down in his hole. 2 nights ago he's out feeding on live brine A-OK no problemo......as of yesterday.... GONE. No-where to be seen. His hole is open (didn't "shut his door" the other night I guess). I can only see so far down in there, but no sign of him. Anyone heard of them becomming victims of a "cave in"? It doesn't really LOOK caved in but as I said, I can only see so far in. ALL other inhabitants of the tank are good as gold. Where oh where has this little guy gone. We miss him dearly He is/was our favorite.