Why did my angel fish die?

I bought three angel fish yesterday and today two die. They were in a lighthouse ornament I have in the tank then one died and then about an hour later the other one died, I also have two goldfish and a a scavenger in the tank... And before you go blaming my Jeeves "that's the scavenger" he doesn't bother anyone. The third angel is just floating near the top of the water.