I'm SO sorry! I've only had my pixie for 3 days and I'm already very attached, so I'm sure you're pretty upset. I don't want to speculate on her cause of death, but I will say that I've only ever used the GE 1 or 2 silicone for windows and doors (as mentioned by Bill) and I've never had an issue. I used it in aquariums with African Clawed Frogs.