birdies and sad fish day

I love watching the birds on my flowers outside my office. The day started well, but when I went outside I found a floating dead fish - my second largest one called Splodge. Rivett, the largest fish was missing and is still missing this evening. I am sad that the two large fish have suddenly died, inexplicably, my friendly pets I have had for over 26 years, bought when we first married in 1988 from the koi farm near Bordeaux.