An investigation is underway after two unoccupied cars caught fire in North Spokane early Wednesday morning. The cars may have been set on fire in the area of Northstar Lane and North Cedar at about 2:30 a.m. on Wednesday, according to Spokane Police Officer John O'Brien. Spokane County Fire District 9 has fire investigators currently looking at the scene for signs of arson, Assistant Fire Chief Doug Bleeker said. Bleeker said they're coordinating with the city on the investigation.