A Pacific Beach woman was killed when the dune buggy in which she was riding overturned in the desert, the California Highway patrol reported. The victem, identified as Bridget Thorton, 20 was sitting in the lap of another passenger on Sunday when the driver of the vehicle attempted to make a sharp left turn while driving on a dirt road, the CHP said. Thorton was a student at Mesa College. Dean Kallson, 29, another passneger, was taken to Grossmont Hospital in La Mesa, where he was listed in stable condition. The driver of the dune buggy, Shawn Raether, 22 was not hospitalized.