The Rock County Sheriff’s Office is investigating a fatal motor vehicle crash east of Janesville.  Sheriff’s deputies responded to a three vehicle crash about 6:30 p.m. Wednesday on Highway 14 near Emerald Grove.  Officials say 57-year-old Janesville man was driving west and crossed the center-line into the path of an east bound 74-year-old driver, also from Janesville.  Both men were pinned in their vehicles and pronounced dead at the scene.  The driver of a third vehicle, which ended up in the ditch trying to avoid the crash, was not hurt.  The highway was closed for more than three hours.