1453: During the siege of Constantinople, the entrenched Byzantines leave a gate unlocked, allowing the invading Turks to pour in and crush their empire.
1527: A 600-man Spanish expedition tries to colonize Florida, loses its ships, finds no gold, and gets routed by natives. Four survivors are left wandering naked.
1912: On the Titanic’s maiden voyage, a lookout neglects to bring binoculars to the crow’s nest to spot icebergs—and, well, you know the rest.
1964: A grad student unwittingly kills the oldest-known tree, a bristlecone pine dating back 5,000 years, when he chops it down to free a stuck tool.
1971: Ford unveils the Pinto, an affordable subcompact sedan that bursts into flames when rear-ended; 1.5 million are recalled.
1977: When lightning strikes NYC’s electric grid, an operator fails to flip some switches in time, resulting in one of the largest blackouts in city history.
1990: NASA spends $1.5 billion to build and launch the Hubble Space Telescope only to realize, once it’s in space, that it takes blurry photos.
1993: Super Bowl, fourth quarter: Cowboy Leon Lett showboats in front of the end zone, giving Buffalo’s Don Beebe a chance to come from behind and strip the ball.
2000: Rental king Blockbuster passes on buying DVD-by-mail upstart Netflix for $50 million. Netflix’s 2018 market value: more than $150 billion.
2013: IT worker James Howells mistakenly throws away an old hard drive containing 7,500 Bitcoins, worth $1,000 when he bought them—and $50 million today.
2014: The French government buys 2,000 new trains that are too big for 1,300 stations. It then spends $60 million to widen the platforms. ￼￼￼￼￼￼
This essay is part of our Art of the Fail series.