(CNN) -- Severe storms with heavy rains, high winds and lightning swept across the Midwest to the East Coast on Sunday, flooding towns from Iowa to Michigan, threatening levees and leaving at least eight people dead.
Six of the deaths were in Michigan, where several storms plowed from western Michigan eastward.
Two delivery workers for The Grand Rapids Press were killed Sunday morning after their car fell into a deep ravine created when a rain-swollen creek washed out a road, the newspaper reported on its Web site.
A woman was killed Sunday afternoon when winds picked up a travel trailer from her driveway and dropped it on her in Michigan's Delta Township, about five miles west of Lansing, according to Sgt. Mark Wriggelsworth of the Eaton County Sheriff's Department.
Two people died when trees fell on them during Michigan thunderstorms Sunday afternoon, including a man in Spring Lake who was riding in a car and a woman who was walking in her yard in Conklin, officials said.
A man drowned in Robinson Township, west of Grand Rapids, an official said. Rising waters overtook him while he was tending a dam, the official said. Watch townspeople fight the flooding »
Meanwhile, a fast-moving lightning storm killed one person and injured four others on a beach at a state park in Madison, Connecticut, Sunday afternoon, according to Dwayne Gardner, spokesman for the Connecticut Department of Environmental Protection.
"They were just out enjoying the nice summer day," Gardner said. "Lifeguards ordered people off the beach, and the lightning strike occurred as the people were exiting the beach."
One person was killed when rising waters swept a car away in Columbus, Indiana, early Sunday, a police spokesman said.
As many as 11 inches of rain fell in a few central Indiana communities during the weekend, testing levees and forcing many to find safety atop rooftops.
The worst-hit areas were communities about 25 miles south of Indianapolis and further west in Terre Haute, with most towns receiving 6 to 10 inches of rainfall, said John Hendrickson, a meteorologist with the National Weather Service.
He said some affected areas hadn't seen a such flooding for 100 years.
Elsewhere in Indiana, officials cast a wary eye at two levees in Johnson County, one of the hardest hit areas. Water spilled over them, but they still held up. A small community downstream from the levee at Princess Lake was trapped as roadways leading out remained submerged Saturday afternoon, Hendrickson said. A hospital in Johnson County was also flooded.
A levee burst in the Iowa town of Parkersburg, still reeling from a deadly tornado that struck two weeks ago, according to the National Weather Service. Flooding from the levee break shut down portions of three interstate highways.
In nearby New Hartford -- which also sustained severe tornado damage last month -- water gushed over a levee, forcing the evacuation of about 650 people who fled 10 miles east to Cedar Falls, said Bret Voorhees, spokesman for Iowa Homeland Security and Emergency Management.
In Mason City, Iowa, people were left without clean drinking water after a floods severely damaged a water treatment plant, he said.
Flood waters continued to rise throughout Iowa on Sunday, with the northern part of the state receiving up to five inches of rain from a single afternoon storms, said Voorhees.
Waters were expected to crest mid-week at the earliest, he said, adding that at least 1,000 people were displaced across the state.
Meanwhile, storms in Nebraska spun out an early-morning Omaha tornado -- a quarter-mile wide -- that moved northeast.
Jeff Leanna, a member of the fire department's community response team, submitted photos to CNN showing houses pushed off their foundations, a flattened trailer and several businesses with their roofs blown off and windows blown out.
"The damage is spotty," he said, but power outages were widespread. "It sort of came out of nowhere. The tornado touched down before the sirens went off."
CNN's Shelby Lin and Brendan Gage contributed to this report.