RENO — Fire lines were holding and evacuations were lifted overnight after a fast-growing wildfire forced some people out of homes and closed highways for several hours north of Carson City, a fire official said Thursday. Truckee Meadows Fire Protection District spokesman Adam Mayberry estimated containment Thursday at 40% and said some firefighting resources were being released. No injuries and no damage to structures were reported, although Mayberry said a geothermal power plant and utility lines were briefly threatened. The fire started Wednesday afternoon near Old U.S. 395 in Pleasant Valley and snarled traffic as it expanded to an estimated half a square mile of rugged terrain. Nearby Interstate 580 between Carson City and Reno was closed during the evening commute while aircraft and more than 100 firefighters from local, state and federal agencies fought the fire in low brush and crackling dry grass. Mayberry said the cause of the fire was being investigated.