That stinks, but that is also very little info. Any pictures of the fish? Any external signs of disease (white specks, black specks, white blotches, flukes, awkward swimming, bite/attack marks, were the two clowns fighting, were they trying to host anything that might have had too much sting, any popping sounds at night that might mean hitchhiker)? What do the other fish look like? How long were they in the tank? Were any of your other fish recently added? Did they hang out near equipment/have you had any equipment act up? There are so many things it could be any information could be important