UPDATE 2-Scorching heat roasts eastern United States
* Power outages leave residents without air conditioning
* Forecasters cut corn crop estimates due to weather
By Ian Simpson
WASHINGTON, July 3 (Reuters) - About 1.3 million homes and businesses in the eastern United States remained without power amid a heat wave on Tuesday, and storm damage and high temperatures forced many Fourth of July celebrations to be canceled.
Violent weekend storms and days of record heat have killed at least 23 people in the United States since Friday. Some died when trees fell on their homes and cars, and heat stroke killed others.
Utilities warned that some people could be without power - and unable to run their air conditioners - for the rest of the week. About 1.3 million homes and businesses from Illinois to Virginia remained without electricity.
Local officials in the hard-hit Washington area vented the frustration of hundreds of thousands of people who endured a fifth day with the lights off and the mercury nearing 100 Fahrenheit (37.7 Celsius).
"People are so angry. They are berserk," Roger Berliner, vice president of the Montgomery County Council in suburban Washington, told WTOP radio.
In the District of Columbia, some 13,000 customers of local power company Pepco are still without power. The city is distributing food to people who cannot cook at home.
"Frankly, the people are just fed up with it. I don't have any power in my own home," Mayor Vincent Gray told CNN.
Thomas Graham, Pepco regional president, defended the utility's performance, saying crews were working around the clock and three of four customers without power had had it restored.
Utilities have called in crews and equipment from other companies as far away as Canada and Texas as they grapple with outages in 10 states and the District of Columbia.
Many Fourth of July celebrations were canceled as local governments confronted damage from the hurricane-force winds and high heat and drought conditions that made firework shows risky.
Threats of wildfires and tight local budgets have forced more than 100 communities nationwide to cancel fireworks celebrations. Towns in Tennessee, Ohio and Washington's Maryland suburbs were among the latest to call off the Independence Day festivities.
But one of the biggest U.S. fireworks parties, held on Washington's National Mall, will go ahead on Wednesday as planned, a National Park Service spokeswoman said.
In another sign of damage from the soaring temperatures, forecasters polled by Reuters have cut their outlook for the U.S. corn crop by 2.5 percent as high heat and lack of rain shriveled what would have been a record harvest.
The largest U.S. home and auto insurer, State Farm, said it had received about 29,000 claims from last weekend's storms, more than three-quarters of them for house damage.
Two of its peers, USAA and Nationwide, said on Monday they had received more than 12,000 claims, with the majority also for homes. The three collectively account for about 16 percent of the U.S. property insurance market.
Temperatures from 90 F (32 C) to more than 100 F (37.7 C) were forecast from the plains to the Atlantic Coast on Tuesday and on Wednesday, the Fourth of July holiday, the National Weather Service said.
The upper Midwest could see more severe thunderstorms like the one that ripped down trees and power lines in northern Minnesota, knocked out the phone system in the city of Bemidji and soaked Duluth, it said.
The death toll from the storms and high temperatures climbed to at least 23 with five more heat-related deaths reported in Nashville, Tennessee; Kansas City, Mo.; Philadelphia; and Virginia.
Much of the damage to the power grid was blamed on last weekend's rare "derecho," a big, powerful and long-lasting straight-line wind storm that blew from the Midwest to the Atlantic Ocean.