Apparently one of the reasons you need multiple smoke detectors in your home is to warn you if another one catches on fire.
I heard from another Realtor this week that a smoke detector in a newer house here in Wasilla malfunctioned, caught on fire and fell to the floor. It burned the carpet on the floor but did not start the house on fire.
There was a warranty on the home from Home Security of America so of course the claim has gone in. Last I heard they were trying to decide whether the home owners insurance or the Home Warranty company would be paying for damages.
This is not an excuse to keep from installing smoke detectors…in fact it is probably a reason to add some battery only smoke detectors to your hard wired ones in case of a malfunction.