Why is Jamestown in so much trouble?

Why is Virginia in such trouble?  As a student of history, the king has asked you to join a historical study team to determine why Jamestown & the Virginia colonies are teetering on the brink of destruction.  What would cause the death rate in Virginia to reach as high as 75% - 80%?  In other words why is the death rate in Jamestown so high?  Your challenge is to examine the clues provided and construct a theory that explains what is happening in the Virginia Colony.  Specifically: Why is this occurring?  Who is dying?  Why has it continued for over twenty years?  Make sure that your theory is based upon the clues provided and explains the connections between them.  The settlers in Jamestown are counting on you.  Good Luck! (Proceed to The Clues)