Authorities in Minnesota are investigating the death of an inmate at the Fillmore County jail.

Sheriff Tom Kaase says staff and emergency responders treated the inmate at about 6:30 p.m. Wednesday but lifesaving efforts "were unfortunately unsuccessful."

In a statement, Kaase said the sheriff's office "extends our deepest sympathy to the victim's family." The sheriff's office has not released the inmate's name or the circumstances surrounding the death.

Kaase says the Minnesota Bureau of Criminal Apprehension is being asked to investigate.