The death toll from storms that devastated parts of the United States rose to 20 as the number of customers without power fell to 1.1 million, officials said. The National Weather Service issued excessive heat warnings Wednesday for portions of Minnesota, Wisconsin, Indiana, Missouri, Illinois and Kentucky, with possible temperatures near or above 100 degrees, CNN reported. Heat advisory warnings were issued for several states, including parts of South Dakota, Iowa, Nebraska and West Virginia. As of early Wednesday, about 1.1 million customers from Indiana to Delaware had no electricity, down from 4 million during the weekend, CNN said. Police and National Guardsman were distributing water and food. \"This has been quite an ordeal,\" Washington, D.C., Mayor Vincent Gray said. The outages were spurred by deadly heat-driven storms that began Friday. At least 17 people were killed in the derecho, a massive storm accompanied by straight-line wind damage; three in North Carolina died in a second round of storms Sunday. Tinder-box conditions and wildfires elsewhere in the United States forced communities to cancel July 4 fireworks displays, The New York Times said. \"The way I look at it, I\'d rather preside over the chamber that canceled the fireworks one year than preside over the chamber that burned the school down,\" said Dale Seward, president of Delphi, Ind., Chamber of Commerce. Cities across Colorado, where several wildfires have been burning for weeks, opted to skip the fireworks, the Times said. Residents of Colorado Springs spent the last week returning to what was left of their neighborhoods charred by the Waldo Canyon fire. Southeastern Pennsylvania and the Chesapeake and Delaware bay areas could see strong storms capable of producing hail, heavy rains and cloud-to-ground lightning Wednesday, AccuWeather.com reported. Thunderstorms also were likely across northern Maine into eastern Quebec, forecasters said, as well as in North Dakota, Minnesota and the southern Canadian Prairies.