The first Alabama prisoner has died after testing positive for the new coronavirus, the state Department of Corrections reported Friday as it confirmed two other COVID-19 cases among inmates.

Dave Thomas, 66, who the prison system described as already terminally ill, died Thursday at a hospital within 24 hours of testing positive for COVID-19, the department said. Thomas, who had been housed at St. Clair Correctional Facility in Springville, had been hospitalized since April 4 to receive critical care related to his preexisting conditions.

Another inmate at St. Clair and an inmate at Bullock County Correctional Facility have also tested positive for COVID-19. The state said it has quarantined a group of inmates out of one dormitory at St. Clair and quarantined an entire dormitory at Bullock

The announcement came after concerns by inmate advocates and health experts that the virus could be particularly dangerous in overcrowded and unsanitary state prisons.

The state prison chief said the system is implementing containment strategies.

“In addition to the numerous, system-wide preventative and precautionary measures instituted to mitigate the spread of COVID-19 in our facilities, the ADOC has been aggressively preparing for this day, which was an inevitability based on what we are seeing across the country and world,” Alabama Corrections Commissioner Jeff Dunn said in a statement.

The department said it is distributing face masks to inmates. Masks are being made at sewing factories at two state prisons.