Has Anyone Been Killed Riding a Mule Down the Grand Canyon?

The easiest way to descend into the Grand Canyon is by mule.  The idea of trusting an animal with my life is scary.  Has a mule ever fallen off the path?

There has been only one fatal accident.  It was of one of the mule attendants, not a visitor.

More recently, on May 4, 2009, a 66-year-old woman was injured when the mule she was riding lost its footing, fell and then rolled over her.  She was rescued by the National Park Service and flown to a nearby hospital.