Questions about the Death of a Friend

A coworker of mine from my previous job died today.  It was sudden and unexpected.  She wasn't too much older than I and she was in excellent health.  What happened?  We won't know what killed her until the tests are complete.  Her husband is in shock.  Who knows, he may be next?

There are many dangers out in the woods.  She was out in the woods hiking.  She had a great time.  She got home and all was well.  Then two days later she became ill.  She went to the doctor, which was unlike her.  The doctor said it was some sort of virus.  Three days later...she's dead.

Was it really a virus? She was a clean person and I'm sure she washed her hands and didn't drink what she wasn't supposed to.  Did she get bit?  What creature in the woods would kill her like that?  The doctor didn't say she got bit, just she caught a virus.  What is lurking out in the woods?  Was she contagious?  Is her husband afraid that he's next?  Are they going to have to destroy everything that she came in contact with?  Is this some new government or terrorist experiment?

So many questions.  No answers.