Coopers Beach residents moved away from windows and one huddled under a bench as a roof was ripped off a house and flung into another.
At least four properties on State Highway 10 were damaged by the what locals described as a "mini-tornado" at about 2.30pm yesterday.
Mangonui Health and Fitness owner Donna Thomson said she was inside the gym at the time with three others.
While they could not actually see it coming, it sounded like thunder, Ms Thomson said.
"There was this terrible roaring sound," she said. "It sounded like something rolling towards us."