You should post a capx using dropbox maybe, it can help when you need assistance.
In your case, you select all the enemies and make the die. It could come from numerous cases... and a simple instruction could correct it. Without the code though, the only general solution I see is, in the event where you remove 1 from health, add a sub event where the trigger is "enemy.health<= 0" and the action is the animation you put later.
Or if you want to keep the animation somewhere else (because multiple ways to die), you change the trigger with a Function call, and call that same function on the sub event I described before.
As you are starting with C2, all this may make no sense, so I strongly suggest, as did LittleStain, that you post a .capx showing the problem the simplest way possible...