MADISON, Wis. — An unusual October tornado has downed power lines and destroyed garages on Madison’s east side, but no injuries are reported.

The National Weather Service confirms a weak tornado swept northeast along East Washington Avenue to Interstate 39/90 Saturday evening. The weather service says a preliminary damage assessment indicates it was an EF-zero tornado with winds of 70-80 mph. The tornado was on the ground for about 10 minutes.

Wind shear and instability caused many showers to rotate, resulting in the tornado.

The Wisconsin State Journal reports the storm damaged the roof of a car wash and ripped the facade from a convenience store.

Steve Peters says high winds toppled a walnut tree that destroyed his back porch and detached garage. Peters says the damage “looked like a bomb went off.”