When out on an outdoor adventure, it's essential to know the signs of a potential flash flood, should you ever be stuck in one. Here is what you should do.

Only a dry riverbed separated his backyard from the blaze. Fire engines rushed into his neighborhood as Olson and his wife drove away. “We left home thinking we’d never see it again,” he said.

But today the concrete bridge built to span the water rises over a dry riverbed of sand and gravel. Tourists still come to Mhamid, drawn to camel treks, camping, and sandboarding.