A Hilo man died early Tuesday morning when he lost control of his car and struck a fence and a building.  Big Island police identified the driver as 40-year-old Tracy S. Pack.  They suspect speed and alcohol were factors in the crash just before 2 a.m. north of the intersection of Kinoole and Puainako streets in downtown Hilo. Pack was traveling south on Kinoole Street when he failed to negotiate a curve in the road, struck a chain-link fence and a building. He was not wearing a seatbelt.  Pack died a short time later at the hospital.