A to Z Blog Challenge - I is for Incident

* A to Z Blog Challenge  - I for Incidents*

There are so many different ways a zombie can be created.  More often than not, it's a virus of some kind, which we see in films such as 28 Days Later, the Resident Evil films, and World War Z.  But there are other things that can cause zombies to rise, too.

For example, in Night of the Living Dead, radiation from a satellite that was sent to Venus causes the dead to rise.  In Re-animator, it's a serum created by science.  In Severed: Forest of the Dead, zombies are created when humans get infected with tree sap.  Sounds strange, but the trees were genetically modified.  Still, it's tree sap nonetheless.

No matter what type of incident occurs to cause the zombies to rise, they are still an unstoppable killing force.  They still cause the downfall of humanity, and we are powerless to fight against them.

What other kinds of incidents in movies and books have led to the creation of zombies?