An ex-student gunned down a University of Arizona (U of A) faculty member on Wednesday, leaving the campus community in total shock.

The shooting went down at around 2 p.m. inside the U of A’s John W. Harshbarger Building, which houses the institution’s Department of Hydrology and Atmospheric Sciences, the Arizona Daily Star reports.

Thomas Meixner — an expert on desert-based water issues and the head of the department — was the only victim in the incident, and he ultimately died of his injuries, according to the Arizona Daily Star.

“This incident is a deep shock to our community, and it is a tragedy. I have no words that can undo it, but I grieve with you for the loss, and I am pained especially for Tom’s family members, colleagues and students,” Dr. Robert C. Robbins, president of U of A, expressed in a statement.

Source: University Of Arizona Professor Shot Dead On Campus By Ex-Student, Police Say