Tragedy struck a Mississippi university poised to celebrate its 90th anniversary when a history teacher was fatally shot in his office, authorities said Monday.

Delta State University was placed on lockdown Monday amid reports of an active shooter on the Cleveland campus.

“Delta State University has confirmed one fatality. Campus remains under lockdown. Please stay inside and away from windows,” the school tweeted.

Authorities identified the victim as Ethan Schmidt, an assistant history professor. State, city and Delta State police, along with the Bolivar County Sheriff’s Department, were on on campus and looking for his killer, the school said.

The North Bolivar County Consolidated School District said all its campuses were locked down and that after-school activities were canceled.

University spokeswoman Jennifer Farish said the Delta State lockdown began shortly before 11 a.m. CT Monday and that students, faculty and staff were advised to take shelter. Students were being evacuated from the school building by building, and Monday classes were canceled.

The Bolivar County Coroner’s office said Schmidt was shot in his Jobe Hall office. The school said emergency management officials had set up a command center on campus.

“Fortunately for us, our public safety officers and university officials have trained many of us for active shooter situations,” Don Allan Mitchell, an English professor, told The Associated Press. “Many students are locked-down in classrooms, and professors and staff members are telling them the protocol. Plus, we are all texting and Facebooking each other to make sure we are safe.”

Gov. Phil Bryant has reached out to University officials, said spokeswoman Nicole Webb.

“Governor Bryant is in communication with President LaForge and with Department of Public Safety Commissioner Albert Santa Cruz,” Webb said. “The governor has offered the full support and assistance of DPS, including the Mississippi Bureau of Investigation and the Mississippi Highway Patrol.”

Caleb Smith was on his way to get breakfast when he got the alert.

“I was just walking toward the building when I got the message, so I turned around and went back to my room,” he said. “I have no idea where the shooter could have been.”

Cleveland is 121 miles north of Jackson. Delta State is a public university with more than 4,000 students on campus.

The school had planned a daylong celebration marking Delta State’s 90th anniversary.