are all your girls in a community?
do the fish appear sick before they die?
what do the bodys look like when u find them? (are they chewed up or anything?)
when was your last water change?
im sry to hear about your losses, we may be able to help you find out why these fish are dieing on you, its not uncommon for a fish to get sick without teh owner knowing and dieing, there are a number of illnesses that dont have symptoms and the fish may not have been acting out of character. but 2 fish in a week sounds suspisious, what are your setups like and stuff, can u kinda run us throgh how you care for your fish, im willing to bet it has something to do with chemicals in the water that shouldn't be there, (like bleech or something else thats not fish friendly)