The Waukesha County Sheriff’s Department says the flash red lights and the audible signal at a railroad crossing in the Town of Merton were working when a fatal accident happened Monday.  The driver of a truck was thrown free by the impact shortly before noon.  Investigators say the man’s vehicle was sitting on the tracks facing south and the Union Pacific Railroad train was traveling east.  The truck driver hasn’t been identified.  Deputies say he was alone in the truck and he died at the scene.