An inmate hanged himself at the Hamilton County Jail shortly after noon on Tuesday.
Sheriff Jim Hammond said at 5:40 p.m. that the man in his mid-30s was on life support at a local hospital.
He said the man tied an article of clothing around his neck and to his bunk. He said he sat on the bottom of his bunk and leaned over until he passed out.
The sheriff said, "We are seeing more of this type method at the jail."
He said the man was facing some serious charges, including possibly kidnapping.
His family has been notified.
The sheriff's office said later Tuesday:
"Hamilton County Sheriff’s Office Corrections Officers, as well as medical staff, responded to the report of an inmate attempting suicide on the fourth floor of the corrections facility. When officers and medical personnel arrived they found the inmate unresponsive. Hamilton County Emergency Medical Services responded and transported the inmate to an area hospital where he is currently listed in serious condition."