Preliminary reports indicate at least three of the four men who died Saturday at the Cimarron Correctional Facility in Cushing had been stabbed, said Terri Watkins, a spokeswoman for the state Department of Corrections.

Three inmates were stabbed to death during an attack or fight at an Oklahoma prison and a fourth died of his injuries overnight, an official said Sunday.

On Monday, the Department of Corrections released the names of the four inmates killed in a clash at a prison in Cushing, and the state Speaker of the House believes the deadly brawl reflects the crisis in our correctional system.

The family said Michael Mayden Jr. was in the Cimarron Correctional Facility for a probation violation. He said this deadly “inmate-on-inmate altercation” needs to be a wake up call to all Oklahomans for the change needed. Whether the brawl occurred in a maximum security housing pod is still not known. It is run by the private company Corrections Corporations of America (CCA). No staff were injured during the fight.

“CCA sent two (correctional) officers with each inmate to the hospital”, the Cushing police chief said.

Watkins said that as a precaution, all Oklahoma prisons have been placed on lockdown, which means that inmates are confined to their cells and their movement inside the facility is severely restricted.

“The Cimarron Correctional Facility is majority understaffed”.

Payne County District Attorney Laura Thomas told KUSH today, “Neither the private prison or DOC has ever submitted or briefed my office on the last riot”.

Gang activity in USA prisons poses a major security problem, as many prisoners belong to rival gangs, such as Bloods, Crips and MS-13, in which members gain status and respect for injuring and killing other inmates or correctional officers, according to website Inquisitr.

“To suggest this incident had anything to do with the facility being privately operated is pure politics”, Burns said in a statement.

The injured inmates were taken to hospital for treatment. Prisons are obliged to protect their inmates, but can be hard to maintain when thousands of violent offenders are housed in close quarters.