The accident happened around 10 pm last night on southbound 99 near Grantline Road. A vehicle driven by the woman was involved in accident with a big rig. According to one account from a passerby, the back wheel of the big rig was on top the car. The driver was pronounced dead at the scene. Another woman and a child that were also in the car received minor injuries. The driver of the truck was unhurt. The coroner has not yet released the name of the driver. CHP is still investigating the accident. Part of the freeway was closed for several hours while CHP investigated.