Avian Flu could cause global depression.
 

Here's an interesting report by Dr. Sherry Cooper and Don Cox of BMO about what could happen if avian flu were to break out. Makes for an interesting 'what if' read. If this were to happen you want to hope that you've tucked away a large chunk of cash.
Just to give you an idea of how big this would be they talk about SARS in Toronto. There were only 252 cases and 44 deaths but the tourism industry lost $500 million and shed 28,000 jobs. An avian flu outbreak would drawf SARS in numbers infected, deaths and regions affected with outbreaks.
http://www2.bmo.com/bmo/files/news%2...vian%20Flu.pdf