Whether it's a cost-cutting move to save on some of the Titanic's three million rivets, or a shortcut taken while building a gladiator stadium in ancient Rome, it takes just a little carelessness to trigger the deadliest engineering failures in history.

From doomed voyages across continents and oceans to covert CIA operations, these missions show that no matter how much preparation and planning are done, things can still turn deadly.

From ancient war machines to devastating weapons of mass destruction, these are the innovations that changed warfare and rank among history's deadliest.

From the Johnstown flood to the Indonesian tsunami, discover how water's power can transform into an unstoppable agent of death.

From mad rulers like Caligula and Ivan the Terrible, to dictators like Mao Zedong and Saddam Hussein who killed by the millions, these are history's deadliest tyrants.

Isolated, deadly, and unforgettable - places like Iwo Jima, Devil's Island, and Snake Island -these isles are home to some of history's darkest stories.

One spark is all it takes. From the Hindenburg disaster to Krakatoa's violent volcanic eruption in 1883, these explosions are among history's deadliest.

From killer hurricanes and tsunamis to earthquakes, floods and fires, these are the deadliest natural disasters ever recorded.