usually worked in the inmate dining hall. Ten hostages were employees of the prison system: two were educators, and one was a guard. Later on, the prison chaplain would also become a hostage. Four prisoners were also held as hostages. On the final day, the inmates tried to escape using chalkboards and hostages as shields. Dominquez was killed in the attempt. Carrasco killed Elizabeth Beseda and then shot himself. Julia Standley was also killed that day. Ignacio Cuevas was executed on May 23, 1991 for her murder. Facility While the prison is officially the Huntsville Unit, the prison's red brick walls led to the nickname "Walls Unit." The prison is southeast of Dallas and north of Houston. The original cellblock had been closed for several years prior to 2011. The electric chair was previously in a building adjacent to the institution's east wall. When the death row was in Huntsville, it was in the East Building. Operations The warden of the Huntsville Unit is in charge of the maintenance of the Captain Joe Byrd Cemetery, the TDCJ prisoner cemetery. Prisoners from this unit are assigned to maintain the cemetery. Release center The Huntsville Unit serves as one of the TDCJ's regional release centers for male prisoners. Most male prisoners are released to be closer to their counties of conviction, approved release counties, and/or residences. Male prisoners who have detainers, are classified as sex offenders, have electronic monitoring imposed by the Texas Board of Pardons and Paroles, and/or have certain special conditions of the Super Intensive Supervision Program (SISP) are released from the Huntsville Unit, regardless of their counties of conviction, residences, and/or approved release counties. Rick Thaler, the director of the Correctional Institutions Division, predicted in 2010 that the Huntsville Unit, which serves as the regional release center for Greater Houston, will remain the TDCJ's largest release center. Throughout the history of the Texas Prison System 90% of male prisoners were sent to the unit for the final portions of their sentences before being released. Starting in September 2010 the TDCJ instead began to use regional release centers for male prisoners. Death penalty The Huntsville Unit is the location of the State of Texas execution chamber. The TDCJ houses male death row inmates in the Polunsky Unit and female death row inmates in the Mountain View Unit. Between 1819 and 1923 the method of execution was hanging until Texas authorized