Cook County Jail in Chicago was placed on lockdown Sunday afternoon because of low staffing levels, according to the Cook County Sheriff's office.
A statement on the Sheriff's website said that staffing levels dropped "below the normal," prompting the lockdown for officer safety.
"While placed on lockdown inmates will be allowed movement for medical reasons, emergencies, and visitation only," the statement reads. "Discharges will also be processed."
It was unclear how many employees did not show up for Sunday's shift.
According to the statement, regular operations will resume "as soon as staffing levels reach the normal level."
"High call offs, such as those we we have experienced today, are unfortunate and put an unfortunate burden on the majority of our dedicated and hardworking staff," a spokesperson for the Cook County Sheriff's office said in a statement. "The compound has been placed on a limited lockdown to ensure staff and detainee safety. We wish to thank our staff for their dedication."
The jail was also placed under lockdown in January when 18 percent of the 793 employees scheduled to staff the morning shift did not show up for work.