Havasupai had a major flash flood back in 2008 that closed the area for almost a year. Some of the damage may never be recovered from, like the natural pools that were wiped out.

During that major flood there was no rain either, it was raining many miles away and all drained into the canyon.
_________________________
No, I am not Bear Grylls, but I stayed at a Holiday Inn Express last night and Bear was there too!