At least 15 people have been killed amid devastating flooding in Kentucky, Gov. Andy Beshear said Friday, and he said he expects the death toll to "more than double." 

The fatalities will likely include children, the governor said on CNN.

Among those killed was an 81-year-old woman, according to the governor.

A flash flood emergency was issued in Kentucky late Wednesday as 2 to 5 inches of rain pounded the Bluegrass State. The governor said there was a chance for another 2 to 3 inches of rain Thursday night or over the weekend.

MORE: 3 life-saving tactics to use if in a car during a flash flood

As of Friday morning, central and eastern Kentucky remain under a flood watch, according to Beshear.

"While rain totals are not expected to be as high, flooding still remains a concern due to saturated grounds," the governor tweeted. "Please stay safe and alert, Kentucky.

The state is combating washed out roads, destroyed homes and flooded schools, according to Beshear.

"Hundreds" have been rescued by boat and many people remain stranded, Beshear said Friday.

Hundreds of residents are expected to lose their homes and it'll likely take families years to recover and rebuild, he said.

Three of Kentucky's state parks are being opened to people who have lost their homes, according to the governor.

The governor has requested federal assistance.

ABC News' Alexandra Faul, Kenton Gewecke and Morgan Winsor contributed to this report.