The Rock County Sheriff’s Office is investigating a fatal head-on crash west of Janesville. The sheriff’s office reports a 48-year-old Janesville man was driving an SUV west on Highway 14 near North Polzin Road about 5:00 a.m. Friday. A Crash Reconstruction Team investigation determined he crossed the center line into the path of a semi. The driver was thrown from his SUV and his vehicle engulfed in flames by the time emergency personnel arrived. The victim was pronounced dead at the scene. The 50-year-old semi driver from Albany was not hurt. The road was closed for more than three hours. The Rock County Medical Examiner’s office will release the name of the victim.