Power Steering is dead

Hey folks,

I got up to go to work today and when i sat in the car to reverse out of my garage, as i tried to steer left, i couldnt do it, my steering wasn't moving, it's very stiff, it would require someone like Chuck Norris or Rambo to move that so as i was being late for work i just left it in my garage, now what you guys think might be the cause of this ?

i was thinking either power steering fluid finished, or pump went kapoot.

any thoughts ?