A wildfire near a heavily populated area in Colorado may have been sparked by a grass mower.

Investigators are still looking into what sparked the fire burned south of Fort Collins, which temporarily triggered an evacuation south of Horsetooth Reservoir on Saturday. However Bob Smith told the Coloradoan that he saw the Spring Glade Fire start as a contractor was mowing his property. He says the contractor hit a rock and either that or one of the gearboxes overheating sparked the fire.

He says it quickly took off in the wind toward an open space area.

The fire spread to about a half square mile (1.5 square kilometers) and has been 95 percent contained.