majority of riverbend's convicts are considered so dangerous they remain on lockdown 23 hours a day. you're about to see firsthand the extreme measures prison staff take to control such an explosive population and discover what can happen when so many offenders have so little to lose. nashville, tennessee, is the world-famous home of country music, but just four miles from downtown is home to this state's most violent offenders. it's a high-tech correctional facility called riverbend maximum security institution. riverbend opened in 1989 and sits on 132 acres. it replaced its 100-year-old predecessor, the tennessee state penitentiary, known as the walls. today, riverbend houses close to