Dead Guppy, Can't Think Why

[Teri]

When I got in yesterday, my b/f told me that one of the fish had died, so he fished it out and flushed it down the toilet. (he isn't a fish lover). Anyway, it was a very pregnant female guppy, I hadn't seen her for a day, but I thought she was hiding and giving birth.
As I didn't see the body, I don't know what was wrong - I had to put down a male guppy last week, but he had had "the shimmies" for a while, was obviously ill, when I last saw this one, on Tuesday, I think, she seemed absolutely fine.
Water stats were normal, and I did a big water change last night, just wondered if anyone had any ideas why she died, and if I should treat the water with anything? All other fishes seem happy and healthy.
Also, bit of a macabre question, but if the b/f hadn't flushed her down the toilet, is there any chance any of the fry might have survived, if I could somehow have got them out? She was very big, larger than my other one who gave birth on monday was.

 

[Tokis-Phoenix]

She could have died of birthing complications if she was very heavily pregnant, happened to one of my female guppys not so long ago. Unfortunately without a body there's not an aweful lot you can do in figuring out what killed her- shimmies in mollys is often brought about by a lack of salt, but shimmies in guppys can be brought about by things like internal bacterial infections sometimes. It may be good to treat the tank with some half doses of Pimafix or "anti internal bacteria" by interpet just to be on the safe side .