NASSAU -- State Police are investigating a one car fatal accident that occurred early Saturday morning.Around 2:20 AM. Marian Hubbard, 20, of West Sand Lake, was driving a 2001 Isuzu, eastbound on ST 20 in Nassau when the vehicle crossed into the westbound lane, struck a guide rail on the north shoulder of the roadway, and flipped over. One passenger, Alicia Hubbard, 18, of Nassau, was ejected from the vehicle. The Isuzu continued down an embankment and flipped over several more times ejecting the driver and another passenger, Nicole Hubbard, 19, of West Sand Lake. Alicia Hubbard was pronounced dead at the scene. The driver, Marian Hubbard, was arrested for driving while intoxicated and transported to Albany Medical Center where she is listed in serious condition. The driver and the passenger who was killed were not wearing seat belts. The investigation into this crash is ongoing and any person with information regarding this investigation is asked to call the New York State Police in Schodack at (518) 732-4644.