A vacant duplex in Joshua Tree was completely destroyed in a fire early this morning. About 2:40 a.m., firefighters arrived at the scene at El Reposo Street and Highway 62 in downtown Joshua Tree to find the 1000-square-foot building fully involved in flames. The fire was reported by a neighbor. The cause of the fire is under investigation, as there was no electricity or gas to the building. Fire fighters were at the scene for about two hours.