An intense snowstorm interrupted spring in the northern plains. With snow more than a foot deep, record cold and winds gusting up to 90 m.p.h., North Dakota state workers got the day off, classes at scores of schools were canceled and travelers were stranded. Five people died when their plane crashed in blizzard-like conditions in Nebraska, and one traffic death was blamed on the weather. The eastern edge of the storm carried heavy rain that threatened to cause flooding in the eastern Dakotas. Thunderstorms caused damage in Arkansas and Oklahoma.