Madison County authorities are investigating the death of an inmate Sunday.

The Madison County Sheriff’s Office, in a statement, said a 47-year-old male was found unresponsive in his cell on Sunday at about 6:45 a.m. The inmate, whose name was not released, was housed alone.

Correctional Officers administered CPR until medical staff inside the jail arrived. The man was pronounced dead at the jail by a Huntsville Hospital on-call doctor.

No foul play is suspected, according to the sheriff’s office. A preliminary investigation has determined the man died by suicide.

According to the sheriff’s office, he was booked into the jail on Nov. 1 on a drug possession charge.

Sheriff’s detectives and CSI are investigating to determine the cause of death. His remains will be released to the Alabama Department of Forensic Sciences, which will make a final determination.