The Brief Cobb County detainee Robert Hardy, 61, died Sunday at Kennestone Hospital after suffering a heart attack in custody. Deputies found Hardy in cardiac arrest on Saturday and rendered aid before he was placed on life support. The sheriff's office is conducting an internal review while the Medical Examiner determines the official cause of death. A 61-year-old detainee died at Kennestone Hospital after going into cardiac arrest while held at the Cobb County Adult Detention Center, law enforcement officials announced Monday. What we know: Cobb County Sheriff's Office deputies found detainee Robert Hardy in cardiac arrest Saturday. Medical staff immediately provided aid, and emergency responders transported Hardy to Kennestone Hospital, where doctors placed him on a ventilator, according to the sheriff's office. Life-saving measures failed, leading Hardy's family to make the emotional decision to end care. Hardy died Sunday at the hospital. Hardy had been booked into the adult detention facility June 11 on charges of first-degree arson, driving over a fire hose, reckless driving and driving on a suspended license. What we don't know: The Cobb County Medical Examiner has not yet released the official cause of death. Officials have also not disclosed how long Hardy remained in cardiac arrest before deputies discovered him in his cell. What's next: The Cobb County Sheriff's Office is carrying out an internal review to verify that staff followed all jail protocols. The agency typically conducts internal reviews following any in-custody death. #fox5atlanta #crimewatchatlanta