* West Virginia hardest hit state
* Heat wave to ease in Midwest, high temps to blast West (Adds two deaths due to storms in Tennessee)
By Ian Simpson
LEWISBURG, W.V., July 5 (Reuters) - Six days after violent storms hit the eastern United States, the state of West Virginia was struggling to recover on Thursday, with nearly a third of electricity customers still without power and new storms putting more people in the dark.
Electric utilities said more than 566,600 homes and businesses were without power from Ohio to Virginia, leaving them without air conditioning amid a scorching heat wave.
West Virginia, with a population of about 1.9 million, was the hardest hit. Utilities warned that some people could be without power for the rest of the week.
A fresh batch of damaging storms that pushed across southern West Virginia, Tennessee, Kentucky and North Carolina on Thursday afternoon caused more outages and the weather was blamed for two deaths in Tennessee's Great Smoky Mountains National Park.
One man riding a motorcycle was killed in an accident blamed on the weather, and a woman died after being struck by a falling tree, said park spokeswoman Melissa Cobern. Numerous trees were knocked down inside the park, blocking roads and stranding motorists who had to be rescued, she said.
Huge trucks loaded with ice and bottled water roared through the picturesque West Virginia mountain resort town of Lewisburg to supply thousands of residents in the region who lacked power or water.
Plants that shut down during the initial power outages have resumed pumping but had not generated enough pressure to supply far-flung residents, Lewisburg Mayor John Manchester said.
Repair crews from as far away as Arkansas have set up a temporary campground on the town's outskirts, where an empty field was filled with dozens of electrical trucks.
Jerry Morehead said he and his crew had been working up to 18 hours a day. "We turned some people on today - did some good work," he said.
Katie Gwynn of Lewisburg said that until her power went back on Thursday, one of her neighbors had kept her refrigerator running with his generator and extension cords for six days - and would not accept any payment.
"The conditions have been ripe for great difficulties, but people have pulled together," Manchester said, noting there had been no deaths or serious injuries in Lewisburg related to the storm.
The temperature in Charleston, the state's largest city, reached 93 Fahrenheit (34 Celsius) on Thursday and was expected to top 100 F on Friday and Saturday before returning to the mid-80s F Monday, according to Accuweather.com.
Adding to the snarl and the strain on local infrastructure, tens of thousands of visitors streamed in to attend a professional golf tournament at The Greenbrier, a famed resort in White Sulphur Springs near Lewisburg.
Thousands more were expected for weekend concerts at the resort featuring Rod Stewart and Jon Bon Jovi.
The continued heat wave was bad news for Midwest farmers, with the corn crop suffering from drought in the middle of a crucial growth phase.
The U.S. Drought Monitor showed an expanding area of abnormally dry and drought conditions in Illinois, Indiana, Ohio and Missouri. Corn prices surged to their highest in over a year and soybeans were near a record high on Thursday as the heat scorched crops.
"It's not only abnormally dry, but now you have 100-degree heat combined with the ongoing drought and it's too much for the crop," Accuweather.com senior meteorologist Alex Sosnowski said, adding that Washington, D.C., could on Saturday break its all-time record of 106 F (41 C) set in 1930.
The Midwest and East should start seeing more normal temperatures next week, when the extreme heat returns to the West and brings triple-digit temperatures to parts of Idaho, Utah, Washington and Oregon.
The temperature in Chicago hit a record 103 F on Thursday, before dropping 19 degrees with the arrival of a thunderstorm in the early afternoon. Summer school was canceled at 21 public school buildings without air conditioning.
Part of Columbus Drive near downtown was closed after the pavement buckled.
Around a ground-level fountain near downtown Chicago's Daley Plaza at lunchtime, more than a dozen people were resting their feet in the cool water.
"Any time you can cool off one part of your body, it helps," said Mary Moore, 56, of Chicago, who was dipping her feet in the fountain during a break from jury duty. She said she didn't mind the sunny weather. "I prefer it to the winter," she said.
The storms last Friday crossed the eastern United States with heavy rain, hail and winds reaching 80 miles per hour (129 km per hour), leaving more than 4 million homes and businesses without power. The storms and the record heat that followed have killed at least 23 people. (Reporting by Mary Wisniewski in Chicago, Scott DiSavino in New York, Kim Palmer in Cleveland, Tim Ghianni in Nashville, and NR Sethuraman in Bangalore; Editing by Andrew Stern, Todd Eastham and Lisa Shumaker)