The dean of the UNC school of public health said in a blog post Monday that UNC-Chapel Hill should shift to all online classes.

Dean Barbara K. Rimer of the UNC Gillings School of Global Public Health wrote that growing numbers of COVID-19 clusters and students socializing off campus without masks and social distancing mean it’s “time for an off-ramp,” or a return to all-remote learning.

The university announced Monday afternoon that all classes will switch to remote learning. UNC reported 324 positive coronavirus cases between students and employees from Aug. 10-16, a 13.6% positive rate. Students make up 275 of the newly reported cases. That’s an increase of 135 cases (130 students and 5 employees) since the Aug. 3-9 data was released.

UNC-Chapel Hill reported four COVID-19 clusters, in Granville Towers, Ehringhaus Community, Hinton James residence hall, and Sigma Nu fraternity, The News & Observer reported.

“The rationale for taking an off-ramp now is that the number of clusters is growing and soon could become out of control, threatening the health of others on campus and in the community and putting scarce resources at risk,” Rimer wrote before the school’s announcement of online classes.