Officials say they had to put one of Illinois' maximum-security prisons on lockdown not because of an inmate riot but because dozens of guards called in sick.
The movement of inmates was limited for most of Friday at the Stateville Correctional Center in suburban Chicago.
Nearly 60 employees failed to turn up to work, an occurrence that Illinois Department of Corrections spokeswoman Stacey Solano called "unusual."
It came a week after more than 100 Stateville prisoners were reportedly bed-ridden by norovirus, a highly contagious flu.
It also took place a day after hundreds of correctional officers and state retirees rallied in Springfield against possible cuts to their pensions, according to the (Bloomington) Pantagraph.