A 61-year-old inmate at the Stillwater prison died at the facility Sunday, authorities said. The man had existing medical conditions and tested positive for COVID-19 on Oct. 20, according to prison officials.

The inmate was taken to a hospital on Saturday, evaluated and released to the prison. He is the third COVID-19 death in a state correctional facility.

More than 750 inmates have tested positive for the coronavirus at the Stillwater prison, which houses nearly 1,280 inmates. More than 150 staff at the prison have also tested positive, corrections officials said.

Prison officials said they are being proactive in efforts to keep the virus at bay after an outbreak at the prison in September. In early October, more than 90 inmates tested positive, the St. Paul Pioneer Press reported.