SUMMIT, Wis. (CBS 58) -- An investigation is underway to determine the cause of an overnight fire in Waukesha County. 

The fire happened around midnight at Stolley's Hogg Alley near Delafield and Venice Beach in the Village of Summit. 

Authorities say the fire started on the outside of the restaurant and worked its way inside. We're told the business has minimal damage. 

No one was hurt.