Lost 2 Fish in 2 Days ??????????

[Black Phantom]

As if one wasn't bad enough. Now I've lost my best fish in the tank. Yesterday I found my Naso Tang doing the "deadmans float". I figured he probably just died of natural causes as I've had him for about five years.
Today my prized Foxface was doing the same thing. For some reason he got stuck to the intake of my Tunze pump yesterday. I figured he had been there for about an hour. When I shut the pump off he seemed to be fine and even picked at some food. This morning he looked ok but an hour later was toast.
All my other fish and corals look just fine.
Does this sound like coincidence. I've had the Fox for about five years as well.
Nothing in my tank is new or has been changed in the last year.
I have had a bit of an Aiptasia outbreak but I'm sure that couldn't have been a factor.
Any help would be appreciated.