An inmate at the St. Joseph County jail was found dead Wednesday morning. The sheriff's department issued a press release saying a jail guard found the male inmate unresponsive at 4:47 a.m. The inmate's name has not been released. Nursing staff and an ambulance were called and attempts to revive the man were made before the man was pronounced dead, the press release said. Police believe the death is the result of natural causes. As part of regular police procedures, the metro homicide unit and the coroner were called to investigate. An autopsy will be conducted, the press release said.