(Preble County, OH)--One area school has closed due to Covid-19. National Trail Superintendent Bob Fischer announced Thursday night that National Trail High School would be closed through at least the end of next week. Two new positives among students have brought the total number to six. Here’s Bob Fischer Thursday night: "These two additional students have contacted approximately 33 other students, bringing our total number to approximately 60 students who are now quarantined. That represents about 20% of our student population." The state’s dashboard indicates no cases among National Trail staff.