Oh my goodness I'm so sorry to hear that. It seemed so sudden as well. I second Marie83's advice, tell both your avian vet and the breeder. I know it must be terribly hard but you can help them out by thinking if there was anything that was different about that night or days before, anything at all however small it might seem. It will help both the avian vet and the breeder to determine what could have caused this to happen and thus give you closure on what happened. It's important part of your grieving process to understand why.
My deepest sympathies





