Both sisters simultaneously and fatally, though?
sounds like maybe they both consumed drugged drinks
If both on real low Salt Diets and add lots of beer.... once call beer patomia(sp) and was thought to only happen to alcholics . Meds like SSRIs are known to cause it
But, if they were both intoxicated, they could have most likely expired without ever really knowing they were in any kind of trouble.
How sad.
They were very close