Kentucky was swamped by wave after wave of heavy rain, unleashing flash flooding that swept a mother and child into a creek, stranded a school bus and forced more than 160 rescues in Louisville.
The rains started Thursday and continued Friday in portions of the Bluegrass state.
In Lee County, authorities searched for the mother and child swept away by rushing water on Friday as rescue workers were attempting a rescue, Kentucky State Police Trooper Robert Purdy said.
The two were stranded in their vehicle in high water Friday morning on an eastern Kentucky highway. Rescue workers lost sight of them about two hours later, Purdy said.
As rain pushed through parts of the South and Midwest, severe thunderstorms were also blamed for the death of a woman who was camping with her family at Natural Bridge State Resort Park in eastern Kentucky.
Meanwhile, thousands of people in south central Kansas lost power amid winds that reached nearly 90 mph downed trees and damaged buildings overnight and early Friday, and a possible tornado was being investigated in Oklahoma.
In Louisville, Simone Wester awoke Friday to the sight of boats carting away her neighbors.
"It looked like a hurricane struck, said Wester, whose apartment complex was surrounded by floodwaters, waist-deep in some places. "I didn't know what to do."
Wester, 20, and her 7-month-old son, Jeremiah, were rescued by a man who removed his socks and waded through the floodwaters toward her. The man, Kevin Mansfield, charted a navigable path and ushered her out of the flooding.
Louisville Mayor Greg Fischer said more than 160 water rescues had been made.
In Powell County, Kentucky, Catherine Carlson, 45, was killed and her husband was injured when a large tree limb fell on their tent, said Coroner Hondo Hearne. Their three children didn't appear to be injured, he said.
The campground where the family was staying was evacuated due to flash flooding, said Gil Lawson, a spokesman for the state Tourism, Arts and Heritage Cabinet.
A northern Kentucky school bus with 16 students aboard was stranded for about three hours by floodwaters that covered roads to schools. The Grant County students and bus driver eventually climbed up an embankment next to the bus and walked about a half mile to higher ground, where they were picked up, said Nancy Howe, a school district spokeswoman.
In Kansas, no deaths were reported but six people were injured in a severe thunderstorm, emergency management officials said. Several buildings were damaged in Newton and the Jabara Airport in Wichita was closed Friday morning because of storm debris on the airfield.
In Oklahoma, the National Weather Service plans to send a survey team to Ottawa County to investigate reports of a tornado touchdown.
The possible tornado near Afton was part of a storm system that moved through northeastern Oklahoma and northwestern Arkansas late Thursday and early Friday.
Elsewhere, heavy rains that drenched parts of southern Indiana with nearly 4 inches of rain sparked flooding that trapped two truck drivers and a motorist in their vehicles Friday before emergency crews ferried them to dry ground.
In Kentucky, more than 6 inches of rain fell in Louisville, and Lexington had received more than 5 inches, he said.
Some cars were submerged by high water on roads next to the University of Louisville's main campus, said school spokesman Mark Hebert. A few campus buildings had water in the basements, he said. Early classes were canceled Friday, but classes resumed by midmorning, he said.
Bill Mattingly, assistant chief of the Okolona Fire Protection District, said floodwaters started pouring into first-floor apartments overnight.
Jefferson County Public Schools in Louisville canceled classes Friday.
Associated Press writer Rebecca Yonker contributed to this report.