power to nearly 1 million customers, killed 1 and injured about 12 others. See also List of derecho events References External links The Southern Great Lakes Derecho of 1991 (Storm Prediction Center) 1991 meteorology Natural disasters in Iowa Natural disasters in Michigan Derechos in the United States 1991 natural disasters in the United States Natural disasters in South Dakota Natural disasters in Wisconsin Natural disasters in Ontario Derechos in Canada July 1991 events in North America 1991 disasters in Canada