A Mercer County hospital was shut down for decontamination after treating prison workers who came into contact with a suspicious substance.

Officials say Grove City Medical Center was shut down Monday starting around 6 p.m. and reopened just after 8 p.m.

This after six employees from Mercer's State Correctional Institute came into contact with a suspicious substance while searching a cell and packing inmate property around 2 p.m. 

Mercer's SCI says all the six employees were taken to Grove City Hospital for treatment with one of these employees needing Narcan for treatment.

Prison officials say the entire hospital, including the ER, was shut down for decontamination.

The SCI says all but one of the employees have been released.

Prison officials say Pennsylvania State Police, along with facility and Department and Corrections staff, are investigating the incident.

They say DOC officials will work closely with PSP, who will determine whether charges will be filed.

"The Department of Corrections values the safety of its employees and has a zero tolerance for drugs entering its prisons. DOC officials will not tolerate this type of behavior by inmates," a release from the State Correctional Institution said.

As of 10 p.m., officials say the prison is on lockdown.