The condition of Monica Chung, 67--one of 12 people aboard a tour van that crashed killing seven while returning to Los Angeles from Las Vegas last week--was upgraded from critical to serious at University Medical Center in Las Vegas, officials said. Chung was a passenger aboard the tour van of Korean residents of Los Angeles returning to Southern California Wednesday from a one-day trip to Las Vegas. The accident occurred just west of the California-Nevada line. Sung Il Kim, 31, the driver of the vehicle, was listed in stable condition at Humana Hospital Sunrise. A spokeswoman at the hospital, also in Las Vegas, said Kim had been moved out of the facility's intensive-care unit. Three people died at the scene of the single-vehicle accident. Three others died a short time later in Las Vegas hospitals, and the seventh victim, Mal Yong Oh, died Sunday.