The doors were only opened in K-81, the maximum-security wing of the prison for the second time this month. Prison officials are saying that the incident could have been a computer "glitch"
"As soon as the doors opened, surveillance cameras captured one prisoner in particular immediately leaving his cell, as if he had anticipated the door opening, and walking down a passageway toward another prisoner, with whom he reportedly exchanged a shank or homemade prison knife. They and two other inmates then closed-in on 27-year-old Kenneth Williams, who leapt over a second-floor balcony railing to escape his would-be assailants and suffered a broken ankle and fractured vertebrae in the fall."
(Source: Wired)