Imac not booting up after accidentally unplugging.

Hello I have a Spring 2009 Imac that I accidentally unplugged this morning. Now when I try to load up, I get the grey screen with the Apple loge. The progress bar starts loading up, get about 1/8th of the way and quits and then the computer just wont load up.

I cant get any of the keyboard commands to work so I can't boot up of the CD or in Safe mode. That's about the extent of my mac knowledge...can anyone help?