Power steering light turned on and the steering wheel was impossible to move?

This morning when leaving for work my power steering indicator light came on and my steering wheel was impossible to move. I was unable to even move my car at all, so I had to call out. I don't know how to go about handling an electric power steering issue so any advice or help would be greatly appreciated. (There was no prior indication of this becoming a problem. The car was driving normal then all of a sudden, the light came on and wheel was stiff).