This morning my mother was on my ibook when I heard her say "what happened?" I go to the ibook and it was off. Not sleeping, completely off.And it took a while to respond to my pressing the power button. She was working on a document and was pressing some keys, but can't remember which and thinks one of them was delete. Is there a keyboard command to shut off the computer using delete, if she was pressing the apple keys or ctrl? This has never happened before and and wondering what went wrong.