Minnesota Correctional Facility - Stillwater, the state's largest prison, is on temporary lockdown after several staff members were possibly exposed to synthetic drugs on Thursday.

Nine employees at Minnesota Correctional Facility–Stillwater were taken to the hospital on Thursday after being exposed to a "stronger-than-expected" dose of synthetic marijuana being smoked by an inmate, causing them to fall ill.

Jeff Vars, president of AFSCME Local 915, the union that represents corrections workers, said in a statement that an incarcerated man at the Stillwater facility and another at a medium-security prison in Moose Lake had died from suspected overdoses in the last week.