A driver in a head-on crash Friday night in St. Clair Twp. has died.

John Jeffers, 55, of Greenbush Road in Camden, died Monday morning at University of Cincinnati Hospital, according to the Butler County Sheriff’s Office. He was transported to the hospital Friday by medical helicopter after a two-car crash about 8:25 p.m. in the 2600 block of Jacksonburg Road.

Jeffers’ passenger in the Chevrolet Cobalt, Karen Jeffers, 55, of the Greenbush Road address, was transported by medical helicopter to Miami Valley Hospital in Dayton with serious injuries, according to deputies. The hospital had no information about her condition Tuesday afternoon.

Thomas Southard, 21, of Oxford-Trenton Road was the driver of the other vehicle involved, a Monte Carlo. He was transported to Fort Hamilton Hospital in Hamilton. Southard was not listed in the hospital’s director on Tuesday, according to a hospital spokesman.

The cause of the crash remains under investigation by the Butler County Serious Traffic Accident Reconstruction Team (S.T.A.R.T.) and the Hamilton County Coroner’s Office.