Why did all the vampires had to die?

well firstly they diddnt die, they live among us. Vampires look exactly the same as to a normal humanbeing except their eyes and skin (eyes are usually much more brighter and recongnisable, and skin is much paler almost white cold, sometimes known as an albino but not always the case). Also Vampires have supernatural powers and a unnatural thirst 4 blood.

Hope this helped