At least six emergency agencies responded to a “mass casualty incident” at Lee Correctional Institution in Lee County that resulted in the seven inmate deaths and 17 other inmates requiring medical attention, the South Carolina Department of Corrections announced early Monday morning.
Lee County Fire and Rescue said in a Facebook post Monday morning that it assisted with the incident at Lee Correctional Institution. EMS crews from Florence County, Kershaw County, Lexington County and Hartsville also responded.
The S.C. Department of Corrections said on Twitter Twitter around the same time that an incident involving “multiple inmate on inmate altercations” in three housing units at the prison began around 7:15 p.m. Sunday. The prison was secure just before 3 a.m., the agency said.
The department said all responding officers and emergency workers are safe and accounted for.

The maximum-security facility located in Bishopville, about 55 miles from Columbia, is home to some of South Carolina’s most violent, longest-serving offenders. In recent years, there have been several large insurrections, including one in which an inmate overpowered a guard and used his keys to free others from their cells.
The seven deaths at Lee Correctional are the most in any S.C. prison in recent history.
The prison has had several violent incidents over the years. Four inmates were killed last year by fellow prisoners at the state’s Kirkland Correctional Institution in Columbia.
Sunday’s fatal fights came three weeks after inmates briefly held an officer hostage and took control of part of a dorm at the Bishopville prison.
An inmate died during a fight in the prison last July.
In January 2016, five inmates were injured in a fight in one of the housing units. Five months later, one inmate was killed and another injured during an incident.
Five corrections officers were injured during a December 2007 attack by three inmates in one of the dorms.
Going back to June 2012, the prison was placed on lockdown after a guard was taken hostage.