Cook County jail in Chicago, home to roughly 8,500 inmates, was placed on lockdown Tuesday after staffing levels fell too low to safely maintain normal operations, officials said.

“On any given day, we might have 10 percent of people call in sick,” Abdon Pallasch, director of public affairs for the Cook County Sheriff’s Office, told the Post. “Today, we had 18 percent.”

He said more than 140 of the 800 workers scheduled on the 7 a.m. to 3 p.m. shift said they couldn’t come in for a variety of reasons. It likely didn’t help that much of the Chicago area got a blanketed in snow Monday evening, though only a couple of inches.

Pallasch said officials decided the lack of staff warranted a lockdown at the jail, which is the biggest single-site jail in the United States (only Los Angeles houses more inmates). Inmates still will be allowed to attend court dates and doctor’s appointments, and to have visitors. But Pallasch said recreation and other “non-essential” activities had been cancelled.

“It’s for the safety of the correctional officers and the detainees,” he said. “We need a lot of officers to move detainees from one area to another.”

Jail officials said normal operations would resume as soon as staff levels return to normal.

This post has been updated.