Maybe you saw this in the latest TechTails, but I couldn't resist emailing the Apple technician who wrote it. RJ Murphy wrote back and sent these photos. His article went as follows:
"A 24-inch iMac was recently dropped off at the service department because it would not power on. This problem arose after the system sat through a house fire. At first glance, we figured there was not much hope for it, as it was completely charred from top to bottom. The plastic housing on the rear of the system had been badly damaged, with melted plastic around the intake and outtake vents. However, the vents remained unobstructed.

After a quick SMC reset, the system powered on and started up just fine. I've since run our suite of diagnostics and stress-tested the iMac with no unfavorable results. How much more resilient can a computer be? I can't say, but surviving a house fire definitely tops the list — though the smoke smell can be quite sickening."
(He took the photos with his iPhone!) Click to enlarge photos.