A lockdown at Jacksonville Correctional Facility lasted for four days this week, according to an announcement from the Illinois Department of Corrections. Officials said the lockdown was prompted by a missing set of keys, including a ‘master key', which was capable of accessing a number of locked areas within the facility.

Assistant Warden Neil Rossi reported the missing keys, which started a lockdown immediately. The lockdown ended on Monday after the keys were not found during searches of the facility. According to officials, Rossi turned his set of keys over to another employee because Rossi was being reassigned to the central office of the department for a short time. The Corrections Department is currently investigating the situation.