Darn really

[Son Of Skyline]

Sorry for your loss. I've lost expensive (to me) fish and its frustrating to say the least. Having said that though, this is one of the risks you take when keeping a predatory animal like a bta. I agree with others that the wrasse was probably already weak and nature was just taking its course in your tank. Can't blame the bta for going "bta" on your fish. If this happened to me, I'd at least let the bta eat the fish. This way the fish didnt die for nothing.