Technology can seem larger than life—as when NASA scientists, say, expertly deposit a car-size, plutonium-powered rover onto the surface of Mars. Yet we are frequently reminded that computer programs are written by people and, therefore, are subject to human error. The Knight Capital Group (KCG) glitch—which cost that company $440 million on Aug. 1 after a new version of its automated trading software went haywire, spewing erratic stock trades—is the latest in a string of costly and destructive coding failures. The damages range from lives lost, to exploded rockets, to homes left in the dark. Here's a list of some of the most significant computer bugs in history.