How do you tell is an orchid is dead?

This is just a question that was inspired by the compost pile part, but I was wondering how one tell an orchid (especially phalaenopsis and cattleyas) an orchid is dead. I thought orchids were dead when a) all the roots were brown, dry crisps or b) all the leaves turned brown/yellow and fell off or c) all the roots were a blackish-brownish mush, but I was wondering what other orchids growers had to say.

I have a phalaenopsis that is recovering from complete root loss. As long as there are healthy leaves, water can be taken up through them to a lesser extent than with roots (humidity must be increased). This is when you do a sphag and bag rescue. Crown rot and complete leaf loss is harder to overcome. I have heard miracle stories where a phal with crown rot started a new plant off the main shoot. The best treatment as with most things is prevention - once a month application of an antimicrobial agent.

Okay. Thanks for the info.