Yolanda Charlton, 53, was flown to a Modesto hospital after a crash on Highway 140 in Merced County Tuesday.
Detectives say 40-year Jason Shetler took his own life by crossing into the oncoming lane of traffic and crashed head-on into a big rig.
The big rig overturned and spilled compost all over the road, the driver suffered minor injuries.
Charlton suffered several major injuries, including a broken neck and broken pelvis.
