I am guilty of fishicide. Or perhaps it's just fishslaughter. It certainly wasn't intentional.
Spyder's betta, Blaze, had been looking sickly for a few days. Tonight I decided that perhaps his water needed to be changed. I got the bowl ready, changing the water, putting in the drops to make the water safe and moved him in. For a while he was looking ... not better but at least more energetic. I left him alone to do his swimmy thing for about half an hour, so I could accomplish a few nighttime chores. When I went back to check on him, he was on the bottom of the bowl.
I really don't even know what happened. I follow the instructions on the care sheets closely. The only thing that I did differently was move him into the new water sooner than I usually do. On all of our previous water changes, I always waited a while before moving him into the new water -- at least 45 minutes -- and this time I only waited about 20 minutes. Or maybe he was more sickly than I thought?
I have no idea, but I feel horrible.
And tomorrow morning there will be keening wails from the children when they find out, and I will feel freshly horrible all over again.