20 Biggest “Oops” Moments That Changed History

On June 28, 1914, Gavrilo Princip was one of the conspirators who attempted to assassinate Archduke Franz Ferdinand during Ferdinand’s visit to Sarajevo. The first assassination attempt was a failure. Later that day, Ferdinand’s driver attempted to flee to a hospital. While escaping, the driver made the wrong turn and stopped the car to go in reverse. By coincidence, the car stalled directly in front of Princip, who seized the moment and fired two fatal shots, killing Franz Ferdinand and his wife, Sophie. Austria-Hungary blamed Serbia, triggering a chain reaction of alliances that escalated into World War I. A simple navigation mistake became one of history’s most consequential accidents.

On April 26, 1986, at the Chernobyl Nuclear Power Plant in Soviet Ukraine, unsafe design, violation of safety procedures, and intentional disabling of safety systems built into the Chernobyl Nuclear Reactor by the operators led to the world’s worst nuclear accident. Ignoring operating guidelines, combined with design flaws in the safety systems and the reactor itself, triggered a power surge and two massive explosions. It unleashed radioactivity across the European continent. It forced emergency evacuations for thousands and created long-term health and environmental impacts, not only in Ukraine and Europe, but across the world.

When the RMS Titanic set sail for the first time in April 1912, it was promoted as one of the most advanced ships ever built. Even after receiving multiple iceberg warnings, the Titanic continued sailing at high speed. After an iceberg was finally sighted, the Titanic crew couldn’t avoid the impact as it was too late to steer the ship. The iceberg opened several compartments, flooding the Titanic. The Titanic had too few lifeboats for all of her passengers, causing more than 1,500 people to die. The impact of the Titanic sinking was immediate. Maritime safety was changed forever, and it remains famous as one of the worst disasters at sea.

In 1928, Scottish bacteriologist Alexander Fleming discovered the accidental beginning of an incredible medical advancement when he returned from vacation to find a Petri dish he had left out, contaminated with mold. Rather than throw the contaminated dish away, Fleming observed that the mold had killed the bacteria that had proliferated around it. Fleming investigated the mold and discovered it was a type of Penicillium. This discovery was made by accident and developed into penicillin, the first widely used antibiotic.

NASA began the Mars Climate Orbiter program in 1998 to examine the Martian atmosphere. However, two of the project’s engineering teams used different measurement systems — one imperial, one metric. This discrepancy wasn’t caught during the calculations that determined the spacecraft’s path. Consequently, the orbiter dove much deeper into the Martian atmosphere than expected and perished. The $125 million mission failed before it had the opportunity to conduct any of its anticipated studies. This case is now famously referenced to illustrate the extensive costs that a singular unit conversion error can incur.

According to ancient Greek epic tradition, the Greeks made an elaborate plan to conquer Troy after several years of fighting and left behind an enormous wooden horse. The Trojans thought they had won the war and celebrated their victory by bringing the horse behind the walls of Troy, despite warnings that the horse was not a gift. During the night, the Greeks came out of the wooden horse, opened the gates, and let the rest of the Greeks in to finally conquer Troy. Although historians debate whether the story is entirely factual, the tale has endured for centuries as perhaps history’s most famous cautionary tale about trusting appearances.

A gigantic storage container in Boston burst on January 15, 1919, unleashing 2 million plus gallons of molasses. It is said that the molasses sped through the streets of Boston, clocking in at approximately 35 mph. Buildings were leveled, and the thick goo even overturned vehicles and trapped innocent bystanders. Twenty-one people died, and about 150 others were injured. In the aftermath of the explosion, investigators found that the storage tank was poorly and hastily constructed and filled to an unsafe volume. The bizarre occurrence yielded the national implementation of new building regulations and engineering standards. This was also one of the most peculiar industrial failures seen in the USA.

In April 1961, the US launched an operation attempting to usurp Fidel Castro, utilizing a battalion of Cuban expatriates in a military invasion backed by America. There was an expectation of rebellion from the Cuban populace along with a considerable underestimation of Castro’s military capabilities. The invading forces soon became stuck on the beach due to a lack of support, and the operation completely collapsed. Within days, most were killed or captured. The fast collapse of the operation granted Castro and Cuba an increase in strength and America a decrease in strength on the international stage, and operated as a reinforcement for the close relationship between Cuba and the Soviet Union and thereby the imminent Cuban Missile Crisis.

Julius Caesar had become Rome’s most powerful leader, alarming many senators who feared he intended to become a king. On March 15, 44 BC, a group of conspirators assassinated him during a Senate meeting, believing they were saving the Roman Republic. Instead, it plunged Rome into years of civil war. The heir of Caesar, Octavian, defeated all the rivals and was the first ever Roman Emperor, Augustus. The conspiracy did the opposite of what was intended: it destroyed the republic and marked the start of a long, new period of Roman history.

On January 28, 1986, the Space Shuttle Challenger exploded just 73 seconds into its flight, killing all seven crew members, including teacher Christa McAuliffe, who had been selected to become the first private citizen in space. Challenger had carefully been evaluated for potential safety hazards, and engineers voiced particular concern about the cold weather compromising the integrity of Challenger’s O-ring seals. After evaluating the safety issues and determining that the potential for cold weather O-ring failure was not a valid reason to delay, the launch proceeded. The Challenger disaster, along with the subsequent Rogers Commission, resulted in drastic and major changes to the decision-making process within NASA.

In 1915, the British passenger ship, Lusitania, was torpedoed by a German submarine off the coast of Ireland. The ship sank in 18 minutes, almost 1,200 people died, and of the deceased, 128 were American. The ship was indeed carrying military supplies, including millions of rounds of rifle ammunition, but the sinking was still widely condemned as an attack on civilians. The US was neutral, but the people’s opinions were against the Germans, and it was a turning point in the history of the US entering the war in 1917.

On March 24, 1989, the Exxon Valdez oil spill occurred when an oil tanker smashed into Bligh Reef, leaving a wake of spilled oil that would destroy wildlife in Prince William Sound. The investigations recognized human mistakes among the main causes, along with the fatigue of employees and a lack of supervision. The ecosystems and the coastal wildlife were devastated by the spill. The legal and logistical consequences of the spill would take years to recover, but the environmental effects would last much longer. The Oil Pollution Act of 1990 was introduced to create new regulations and safety improvements in the transportation of oil. Subsequently, double-hulled oil tankers would be mandated.

Leading up to the attack on Pearl Harbor on December 7, 1941, the United States government had several opportunities to anticipate the strike, even as tensions with Japan escalated toward war. On the day of the attack, radar operators detected a large number of aircraft approaching Oahu, but the contact was dismissed as an expected flight of American bombers. Because of many intelligence failures, the U.S. failed to anticipate the planned sneak attack. That attack on the American military presence killed 2,400 Americans and was the reason that the United States joined WWII.

On January 1, 1962, The Beatles had their audition with Decca Records in London. Even after listening to their music, the company declined to sign them, labeling the popularization of guitar-based groups as a passing trend and predicting they wouldn’t be commercially successful. Instead of The Beatles, Decca signed another group. A short while after, producer George Martin signed The Beatles to EMI’s Parlophone label, which would go on to be one of the best-selling acts in music history. Decca’s decision would go on to be one of the entertainment industry’s most famous missed opportunities.

On April 14, 1994, two U.S. Air Force F-15 fighter jets over Northern Iraq mistakenly identified two U.S. Army Black Hawk helicopters as enemy aircraft and engaged them. Despite several opportunities to correctly identify the helicopters, communication failures and identification errors led the pilots to launch missiles. All 26 people aboard the helicopters were killed, including American, British, French, Turkish, and Kurdish personnel. Extensive reviews were conducted to examine the failures of the identification protocols and the critical nature of communication and identification in highly dynamic and confused battle environments.

One of the most significant ancient centers of learning was the Library of Alexandria in Egypt. It housed scrolls on almost all subjects from all eras. For a long time, it was believed that a huge, singular fire was the cause of the loss of the library. However, the decline of the library was most likely the result of a series of smaller, unfortunate events, including wars and politically driven actions during the centuries. Eventually, conflicts resulted in fires, new political leaders caused the library to lose funding, and the library slowly disappeared. This led to many of the ancient works being completely lost for a long time. Because of this, countless ancient works are believed to have vanished from history, a loss many historians still consider a tragedy for human knowledge.

Tacoma Narrows Bridge in Washington State opened in July 1940 and collapsed in November of that same year. During strong winds, the bridge twisted and oscillated. There was a lack of understanding of how wind can have an aerodynamic effect and create a force that caused the bridge to act the way it did. “Galloping Gertie” was the name given to the bridge. There were films that documented how the bridge acted before it completely disintegrated and fell into the water. While unfortunate, the only casualty in the disintegration of the bridge was a dog. The failure of the bridge gave way to many innovations in bridge design and engineering, and created many advances in regard to wind resistance.

In April 1970, Apollo 13 was NASA’s attempt to land its third crew of astronauts on the moon. After two days, an oxygen tank exploded. Years of poor manufacturing and design, combined with damage caused during earlier support operations, culminated in the explosion. This damaged the spacecraft and forced the crew to abandon their attempt to land on the moon and instead develop a separate plan to survive. Through a large team effort and resourceful engineering, both NASA and the crew managed to make it back to Earth. This also served as an example of one of the greatest rescue operations in history and, therefore, is famously not considered a failure.

Coca-Cola launched a sweeter drink called New Coke in 1985, following basic taste tests with Coca-Cola and Pepsi. Coke executives believed their competitors launched their products with a secret sauce and that taste tests would eliminate the guesswork. Instead, the taste tests suggested that consumers preferred the sweeter taste of New Coke over both original Coca-Cola and Pepsi. However, executives woefully failed to forecast the emotional resentment their customers would feel. The media especially had a field day with the New Coke fallout. Lots of new advertising campaigns began simply by demanding the return of “Classic Coke.” New Coke had thoroughly and utterly failed in less than three months.

On May 6, 1937, the German airship Hindenburg was almost finished with a transatlantic flight, but caught fire as it was trying to land in New Jersey. The blaze spread rapidly, destroying the enormous dirigible in less than a minute and killing 36 people. The exact cause has never been completely agreed upon, but the most likely explanation is a combination of a hydrogen leak and an ignition source. The disaster made the public turn away from airships and instead prefer airplane travel.

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