sudden death?

[Hilary]

Even if something was wrong with the food or water, you wouldn't have found all four dead at the same time. Even a virus would taken them out one or two at a time. That really sounds to me like something environmental (in the air). You weren't home so no cooking, but did somebody clean that day? Some cleaning products can kill small birds, and I would definitely avoid the air fresheners (are you sure they couldn't have gotten a good whiff of that?). Did you use bleach at all when you cleaned the cage? They have to be out of the cage when bleach is used, and the cage rinsed really well before the birds are put back in. So sorry!