The University of North Carolina at Chapel Hill, one of the largest schools in the country to bring students to campus for in-person teaching, said Monday it will pivot to all-remote instruction for undergraduates after testing showed a pattern of rapid spread of the novel coronavirus. Officials announced the abrupt change just a week after classes began at the 30,000-student state flagship university. They said 177 cases of the dangerous pathogen had been confirmed among students, out of 954 tested. Another 349 students were in quarantine because of possible exposure to the virus, they said. The remote-teaching order for undergraduate classes will take effect Wednesday, and the university will take steps to allow students to leave campus housing without financial penalty if they wish.