Ken Burns' documentary about the ''black blizzards'' that swept across the Great Plains during the 1930s is at once rigorously sourced and heartbreakingly emotional. Burns and fellow producer Dayton Duncan make clear that this ''10-year apocalypse'' was both natural (an unprecedented drought) and man-made (farming technology). As one of the more than two dozen survivors interviewed here explains, ''We were just too selfish and we were trying to make money.''
The human suffering to be seen here is extraordinary. In vintage footage, families hunker down in their homes, tape windows and doors, and wear cloth masks to keep from inhaling the dust mostly to little avail. There are grim scenes that almost defy belief. Plagues of jackrabbits invaded some areas, further destroyed scant food crops, and, for lack of any other method, had to be herded by farmers and their families, who clubbed the animals to death. Some of the survivors, who were children at the time, cry on camera at the memory. The Dust Bowl plays out like Little House on the Prairie, but as grand tragedy. A-

