Welcome to BYC. A little more information will help us to help you. How old was the bird in question? You say you "rinsed off" the bird -- what was the reason it needed to be rinsed, how did you do the rinsing and did you dry the bird thoroughly afterwards?
i dont know the birds age. but the bird was old enough to lay. she was about 6.5 to 7.5 lbs
i rinsed the hen with the hose using a light showering sprayer.
the hen was dirt and i rinse/ give them a bath them once a month or so
this are the largest i have ever grown this birds
and i dry its self off before i put it back
i live in az
i have given this birds a bath before this and they were fine
there are a few folks who claim to have mastered keeping CX alive into adulthood but it is not a common practice. I doubt the death had anything to do with giving it a bath. I've butchered them at various ages and they are prone to heart problems especially if grown out fast for meat. when they go down hill it can be without warning. food rationing and exercise seem to help extend their life but they don't tend to last as long as other breeds.