In a zombie apocalypse, a widespread (usually global) rise of zombies hostile to human life engages in a general assault on civilization. Victims of zombies may become zombies themselves. Here are a few things you'll definitely need if a zombie apocalypse arises, starting with the tank you see above. Continue reading for more.
This causes the outbreak to become an exponentially growing crisis: the spreading "zombie plague/virus" swamps normal military and law enforcement organizations, leading to the panicked collapse of civilian society until only isolated pockets of survivors remain, scavenging for food and supplies in a world reduced to a pre-industrial hostile wilderness.