The Nebraska Department of Correctional Services reported an inmate death Wednesday evening at Tecumseh State Correctional Institution.A statement from the department says 65-year-old Robert Mahler died at Johnson County Hospital. Mahler was serving a sentence of 50 to 81 years on charges in Dixon County, including two counts of vehicular homicide and second-offense driving under the influence.The inmate's cause of death has yet to be determined.Per the department's standard procedure in light of inmate death, a grand jury will conduct an investigation.