We went to the South Rim of the Grand Canyon and were quite impressed....by the stupidity of some people! Lots of people were testing fate by standing on the very edge of the rim. They don't publish it much but people do go over the edge quite often. There is no railing and I think people just figure it must be safe because otherwise there would be a rail. Just a few months ago a grandfather died when he stepped back while having a picture taken. Notice in the photo how the edge can be undercut but not visible from the top!
We ended up going back to the campsite because it was so disturbing.