On September 16, 1999, at 2147 hours Pacific daylight time, an America West flight 2569, an Airbus A320-231, N628AW, encountered turbulence while on descent over Beatty, Nevada. The aircraft was not damaged; however, three flight attendants and seven passengers received minor injuries, while one passenger received serious injuries. The aircraft was being operated as a scheduled domestic passenger flight by America West Airlines, Inc., under the provisions 14 CFR Part 121, when the accident occurred. The flight originated in Seattle, Washington, at 1955. Visual meteorological conditions prevailed at the time and an IFR flight plan was filed. The captain reported that he was at flight level (FL) 250 about 40 miles DME southeast of the Beatty VHF omni-directional radio range (VOR). He had been deviating around thunderstorms while using his airborne radar to identify severe cells. It was a dark night and he had been unable to make visual contact with the severe weather. The turbulence encounter lasted about 5 seconds with one large "bump" that was accompanied by about a 100-foot altitude gain in less than 2 seconds. After the event, flight attendants reported injuries to several passengers. The captain then contacted the company's Las Vegas flight operations and requested that emergency medical equipment meet the aircraft at the gate. The captain stated that he had turned on the seat belt sign 45 minutes before the accident due to "light chop" that he had encountered earlier in the flight. He made a public address (PA) announcement in which he told the passengers to return to their seats and to fasten their seat belts. About 20 minutes prior to the accident, he directed the flight attendants to suspend service and to secure the cabin. Finally, he made one last PA announcement advising passengers that there was an increased chance of turbulence during the remainder of their flight. According to statements from two of the flight attendants, one or more of the injured passengers were out of the seats when the turbulence was encountered. Emergency medical personnel met the aircraft at the gate, transporting six passengers to area hospitals. The three flight attendants were treated by paramedics at the scene and released. Although they were offered medical attention, two of the eight injured passengers refused medical treatment.