(Reuters) – West Virginia declared a state of emergency amid the worst flooding in more than a century that killed at least four people and prompted rescues of hundreds of others forced to evacuate swamped homes, officials said on Friday.

The mountainous state was pummeled by up to 10 inches of rain in a single day on Thursday, causing rivers and streams to overflow, National Weather Service meteorologist Frank Pereira said.

“The flooding we experienced Thursday and into today is among the worst in a century for some parts of the state,” Governor Earl Ray Tomblin said.

The governor declared a state of emergency in 44 of 55 counties and deployed up to 150 members of the West Virginia National Guard to help rescue efforts on Friday.

“Rivers hopefully are going to crest sometime today between noon and tonight,” said Tim Rock, spokesman for the West Virginia Division of Homeland Security and Emergency Management.

“Recovery and rescue is expected to last through the weekend,” he said.

Three people died in the flooding in Kanawha County, the most populous in the state, including a woman in her car, a senior citizen and another person, as well as one person in Ohio County in the state’s northern Panhandle, Rock said.

“There have been towns that have been completely surrounded by water,” Rock said. “People say there is 8 to 9 feet of water in their house.

“It’s at least into the hundreds forced to get emergency shelter,” he said. “Even if you can get back into your home, who knows what kind of shape it’s in.”

West Virginia received one-quarter of its annual rainfall in a single day, Pereira said.

“It was multiple rounds of thunderstorms that continued to move across the same area, a relatively small area, and the mountainous terrain exacerbated the flooding,” Pereira said.

Rains eased on Friday with only scattered showers expected, he said.

The storms that drenched West Virginia were part of a severe weather system that has swept through the U.S. Midwest, triggering tornadoes.

(Reporting by Barbara Goldberg in New York; Editing by Jeffrey Benkoe)