What would you do ??

Ok here is something I ran through my head after watching zombie movies.

What would you do if something like "28 Days Later" or " Dawn of the Dead " type of scenario actually happened ?

Now first off I am in the military and I own a few "legal" firearms so I would not be too worried about personal defence but has anyone really thought about what you would do ? I asked my sister this question and she said she would probably off herself... Now to me this seems crazy ( yes more crazy then zombies running around ) But what could or would you do ?

(Now this is obviously hypothetical and I do not beleive anything like this this could or would happen. )