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 drug kingpins and serial killers, to pirates, assassins, and murderous con men, these are the criminals whose bloody legacies earn them a spot among "History's Deadliest."