Why would you die if you jumped into an electrically charged pool of water?

I was watching Syriana in which a swimming pool light has failed so the water is charged with electricity. This is ogous to when people drop toasters in swimming pools. The thing is that I would have thought the electricity would take the easiest route to earth, which would only be you if you were still touching the sides and the pool was insulated from earth itself. So why does the electricity travel through the higher resistance material (the body)?? Or if it doesn't, how does it kill people??