We went there two summers ago and it is very beautiful but the whole time in it, I was thinking about the group of 11 tourists that drowned in there in 1997 during a flash flood created by rain many miles away. The guide was the only survivor of that group. I believe the Native Americans that run the canyon tours have a much more rigid protocol when rains occur higher up.
It was closed the day before we went because of rain. They used to close for wind too. It can reach 100 mph in the slot. Our guide said they now allow tours during wind. He said he had been in 80 mph before. He was a big boy and had a hard time standing.
The people in 1997 were in the lower canyon. We were in the upper. In 2010 some people were injured in a flash flood as well.