An inmate injured three security staff at Oshkosh Correctional Institution Thursday, sending two to the hospital, the Wisconsin Department of Corrections confirmed.
The inmate-on-staff assault happened the evening of July 20.
The two staff were treated and released, the DOC said.
The DOC has referred the incident to the Oshkosh Police Department and initiated an internal investigation.
Oshkosh Correctional was locked down in June after inmates overdosed and contraband drugs were found in the prison.
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