Nature and politics kill far more people than technological accidents but failures of machines still take a toll on both a personal and social level. Separating machine failures and negligent maintenance from unforeseeable circumstances isn't easy and no doubt there are some accidents worthy of mention that we've missed. In any event, these are the eleven worst tech-related disasters where mechanical or engineering failure played a significant role. And by "worst," we're considering death toll but not using it as the exclusive metric. Some disasters like the destruction of the space shuttle Challenger resulted in only a few deaths but nonetheless had a worldwide impact.
Seven people died with the Space Shutter Challenger flew apart in flight on January 28, 1986, including Christa McAuliffe the "first teacher in space." Like the disintegration of the Space Shuttle Columbia, which also resulted in the deaths of seven crew members, Challenger's end shook the American psyche and marked the beginning of the decline of American's manned space program. The accident is blamed on the failure of an O-ring that sealed the shuttle's rocket booster.
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