Chilling story, the key point to me as a programmer is:

>According to Petrov and other sources, the false alarm was eventually traced to the satellite, which picked up the sun's reflection off the tops of clouds and mistook it for a missile launch. The computer program that was supposed to filter out such information was rewritten.

Every programmer should read this as a reminder of how a software bug can have catastrophic consequences. And I know it's hard, as deadlines come closer, the time dedicated to find bugs drops accordingly.