The Ohio State Highway Patrol reported a two-vehicle crash on US 23 Monday at its intersection with Crouse Chapel Road.
64-year-old Reda J. Castle of Chillicothe was northbound on US 23 with passenger 41-year-old Tia M. Doss of Chillicothe in a 2010 Hyundai Sonata.
They collided with a 1994 Honda Accord westbound on Crouse Chapel Road, driven by 20-year-old Henry Allan Clay Junior of Lucasville, with passenger 18-year-old Kadiah Looney of Waverly.
Clay failed to yield from the stop sign.
Clay was conscious but in serious condition, and was flown to Grant Medical Center in Columbus.
All other occupants were transported to Adena Medical Center with non-life threatening injuries.