ST. LOUIS (AP) -- A powerful spring storm system stretching from southern Texas to northern Michigan unleashed a wave of weather extremes on the Midwest on Thursday and threatened to bring its mix of hard rains, high winds and severe thunderstorms to the East by the weekend.
The massive system was wreaking havoc from the Rockies to the Rust Belt, and officials were blaming two road deaths Thursday on the storm.
Up to a foot of snow was expected in parts of Minnesota and the Dakotas. Snow and ice closed highways in Colorado and Wyoming. Rivers surged beyond their banks from downpours in Missouri, Iowa and Illinois. Tornadoes caused scattered damage in Oklahoma. Hail caused a wreck that injured a high school teacher and her students. Lightning temporarily knocked out a nuclear power plant. Rain caused a sinkhole that devoured three cars in Chicago.
In the Plains and Midwest, seemingly every community was under some sort of watch or warning.
Alex Sosnowski, a meteorologist for AccuWeather, said the storm's biggest punch had come from its intense rainfall: "There's been a general 3 to 6 inch swath of rain from portions of Oklahoma all the way up to southern Wisconsin."
The system will thin out as it heads east but could still spell trouble in the Appalachian Mountain region Friday and in some spots along the East Coast by Friday night, Sosnowski said.
Midwesterners will be glad to see it go.
Minnesota State Police say 16-year-old Jonathon Pohlen of Houlton, Wis., was killed Thursday afternoon when he lost control on snowy Interstate 94 in eastern Minnesota, crossed over the median and collided with a truck's trailer.
Meanwhile, flash floods are being blamed for the death of an 80-year-old motorist south of St. Louis. Police in De Soto, Mo., said the woman's car was swept Thursday off Highway E into Joachim Creek. The woman was not immediately identified.
In Clarksville, Mo., a small, scenic Mississippi River town about 60 miles north of St. Louis, some 100 people were working feverishly to build a makeshift levee of gravel, plastic overlap and sandbags in a bid keep downtown dry. The heavy rain caused a sudden surge in the river, with a crest expected by early Sunday.
"I'm confident it will work, but I'm not confident we're going to get it done in time," Clarksville resident Richard Cottrell, 64, said of the sandbag levee. "It's a race against the clock."
City Clerk Jennifer Calvin said the Federal Emergency Management Agency was bringing in 500,000 additional sandbags, but the nearest available gravel had to be trucked in from nine miles away, and there weren't enough available trucks to expedite the effort.
The Mississippi is expected to crest 8 to 12 feet above flood stage at several spots in Iowa, Illinois and Missouri. The Missouri River was also expected to exceed flood stage by up to 10 feet at some Missouri locations.
Other rivers were rising quickly, too.
The town of Wyoming, Mich., evacuated about 25 homes in the path of the flooding Grand River. The Grand Rapids suburb called in all available police, firefighters and public works employees to help with sandbagging.
In suburban Chicago, Nick Ariano helped rescue a friend's grandmother, who became trapped in a home filling with water after a branch of the flooding DuPage River spilled over its levee.
Ariano, his friend and another man raced to a sporting goods store to buy inflatable rafts, then paddled out to the home and got Mille Andrzejewski, in her mid-80s, to safety. The three friends got some enjoyment out of the raft ride, despite the eeriness of floating over submerged cars and mailboxes.
"As kids growing up we used to raft down the river," Ariano said with a laugh.
About 60 miles southwest of Chicago, Morris Hospital in Grundy County began evacuating 44 patients to other hospitals after a nearby creek and the Illinois River rose and water crept into the basement, spokeswoman Janet Long said. Elective surgeries scheduled for Friday were canceled, although the emergency department remained open, the hospital said on its website.
In Gary, Ind., a flood-fighting drill scheduled for Friday was canceled -- because of real flooding. Sandbagging operations were under way along the Little Calumet River.
Flash flooding was common. In Utica, Ill., the fire department evacuated a mobile home park. In Marshall County, Ill., boats were needed to rescue trapped morning commuters.
In Ava, Mo., a school bus carrying several children stopped because of water on the road. The driver turned around to go back, only to find flooding behind him, too. The driver and kids waited at a nearby home until help arrived.