>Back in 2005 I was at school when a local radio station had a water drinking contest. A woman died.

You're really oversimplifying this, the contest was to drink as much water without peeing so you could win a Nintendo Wii ("Don't pee for a wii"). If you don't pee you offset your body's electrolyte balance and can die. It's not reasonable to expect most people would know this, and the woman that died obviously did not.