Washington, Jul 3 (IANS): Three days after a ferocious summer storm, about 1.7 million people, from the capital city of Washington through 10 states from Indiana to Delaware, are still without electricity even as they battle unrelenting heat .

Making up more than half of those knocked powerless Friday night, the total included about 410,000 in West Virginia, 400,000 in Ohio and 340,000 in Virginia, according to CNN. And officials said some may not get power back until week's end.

At least 16 people were killed from Ohio to New Jersey in the 'derecho' -- or massive storm usually with straight-line wind damage -- while another three in North Carolina died in fresh storms Sunday, the news channel said.

Cities and towns in the Midwest, Mid-Atlantic and Southeast have endured temperatures in the high 90s and above 100 degrees Fahrenheit since, in some cases, the middle of last week.

As utility companies continued to battle massive power breakdowns in Washington metropolitan area about 419,400 businesses and households making up 22.3 percent of customers remained without electricity Monday afternoon, the Washington Post reported citing utilities' Web sites.

That was down from 34 percent of households and businesses late Sunday afternoon, and hundreds of thousands more who had no power Friday night and Saturday. But some areas experienced an increase in power failures Monday as utility companies sought to deal with the overall power crisis.

The weatherman predicted slightly cooler readings - in the low 90s - for Monday, Tuesday and Wednesday, after days of record-breaking heat in which the mercury approached 100 degrees Fahrenheit.

But the National Weather Service also warned of extremely hot and threatening weather again by Thursday, with heat indexes of 105 and readings in the upper 90s through the weekend.