Trying to figure out why one of my FBT's died..........

[FBTmom]

Hello,
This morning my son noticed one of our FBT's underwater, and on closer inspection saw he was not alive. When I got home from work I took a look at him (in a bucket of shallow water; not still in the tank, of course) and it looks to me like he was part way through shedding. His legs and face still had the white skin coating on him. Maybe it isn't shed, but it just looks like it.

I had just done a water change a couple days ago, and all the toads had a good feed of crickets. He was as healthy as could be, that I could see, and even now he looks healthy. Not a mark or blemish on him. His weight is good and his color is good. He died for no apparent reason, and it just doesn't make sense.

The rest of the toads in the tank look fine. They're all healthy and active. During a shed, can something go wrong? I just don't know what to think, so I'm reaching out and asking anyone who may have a suggestion as to what could have happened.

Thanks for any responses,
Diane