WASHINGTON - At least 23 people in West Virginia have died in the U.S. state's worst flooding in more than a century, and hundreds more have been rescued from swamped homes, officials says. Nearly 10 inches of rain have so far fallen on parts of the mountainous state, trapping only 500 people in a shopping center in Elkview, near the capital Charleston, after a bridge was washed away.

Many others have been trapped elsewhere and rescue workers had to pluck them from rooftops and fast-moving waters as rivers around the state were reaching historic levels on Friday.

"The damage is widespread and devastating. Our focus remains on search and rescue," Governor Earl Ray Tomblin told a news conference Friday. "I had planned to fly around the affected areas myself today but wasn't able to because all state aircrafts are currently being used for rescues," Tomblin said.

The heavy rainfall prompted the National Weather Service to describe it as a "one-in-a-thousand-year event." Among the dead was a 9-year-old boy, whose body was found near the Ohio River on the Ohio border in Ravenswood, Jackson County.

Also, three others were reported to be dead in Kanawha County, while another died in Ohio County in West Virginia's northern panhandle. The storms have left almost 500,000 without power and many houses have been swept away.

"There's been a ton of areas that have been hit hard," Danielle Banks, a meteorologist for The Weather Channel, said. Officials declared a state of emergency Thursday night in forty-four counties, mostly in the southeastern part of the state.