"Antelope Canyon is just a deep crack in the of northern Arizona, so narrow that hikers can hold out their arms and touch both sides. A favorite of desert photographers, in recent years it also became a regular stop for guided tours. Last year as many as 20,000 people climbed down to marvel at the swirling stone sculpted over eons by floodwaters. On Tuesday, as a dozen hikers descended into the slot canyon on ropes and ladders, a thunderstorm hit 15 miles to the south. In red-rock country, the ground doesn't absorb rain. Water runs off into washes and races downhill. The final destination for this storm's flash flood was Lake Powell; the last three miles would be through Antelope Canyon."