One semi-truck was destroyed and two others were damaged in a fire outside a business in Middleton Thursday, an official said. Middleton Fire Chief Aaron Harris said firefighters responded to a report of a semi on fire at the UPS distribution center in on Murphy Drive. A Dane County Communications dispatcher said the center received a call at 11:25 a.m. reporting that the front end of a semi was on fire. Harris said a total of three semis parked next to each other in a row of more than a dozen were involved in the fire. The middle semi was destroyed, and the two neighboring semis were damaged. The cause of the fire was undetermined Thursday, Harris said. No one was injured and the investigation is ongoing.