GREENSBORO, N.C. -- Authorities declared a local state of emergency in Greensboro, North Carolina, after a tornado caused damage in several locations around that city. Greensboro police said in a tweet Sunday that there also has been one storm-related fatality in Greensboro, but they gave no immediate details of that death.

The National Weather Service confirmed Monday that a tornado with 135 mph winds rumbled through Greensboro on Sunday, leaving thousands without power and canceling classes. Some roads were blocked by downed trees and power lines.

Earlier media reports said high winds damaged at least seven homes and destroyed one mobile classroom at an elementary school.

This is the back of Hampton elementary pic.twitter.com/5bnjpllKZN — Danielle Battaglia (@DBattagliaNR) April 15, 2018

The statement says emergency crews are conducting checks in the areas affected and urged anyone needing immediate shelter to head to a local high school. Separately the city of Greensboro tweeted that damage was "prominent" but that a tornado had not been immediately confirmed by the National Weather Service.

Tornado not confirmed by NWS, but damage is prominent. Please be safe and beware of downed power lines. Watch for blocked intersections. — City of Greensboro (@greensborocity) April 16, 2018

The storm system dumped 2 feet of snow on parts of the Upper Midwest and coated roads with ice before plowing toward the Northeast and mid-Atlantic.

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The system prompted Enbridge Energy to temporarily shutter twin oil and gas pipelines in Michigan that may have been recently damaged by a ship anchor strike.

The Line 5 pipelines were temporarily shuttered Sunday afternoon due to a power outage at Enbridge's terminal in Superior, Wisconsin, Enbridge spokesman Ryan Duffy told The Detroit News. Enbridge decided to shut down the twin pipelines until weather conditions improve in the Straits of Mackinac, which links Lake Huron and Lake Michigan, Duffy said.

In addition to the Greensboro fatality, three other deaths were blamed on the weather.

A sleeping 2-year-old girl in Louisiana was killed when a tree fell on her family's recreational vehicle early Saturday. A Wisconsin woman was killed when she lost control of her minivan on slick roads and veered into an oncoming SUV. And an Idaho truck driver was killed when his semitrailer struck a semi in western Nebraska that had been stranded on a highway by the bad weather.

At Minneapolis-St. Paul International Airport, where more than 13 inches of snow had fallen, 230 flights were canceled Sunday. Two runways were open, but winds were strong and planes were being de-iced, spokesman Patrick Hogan said. On Saturday, the storm caused the cancellation of nearly 470 flights at the airport.

The wintry grip on the Twin Cities continued to keep the boys of summer off the diamond, forcing the postponement of the third straight Minnesota Twins-Chicago White Sox game. The New York Yankees and the Tigers were rained out Saturday in Detroit and had planned to play a doubleheader on Sunday, but those games also were postponed. The Los Angeles Angels at Kansas City Royals, Atlanta Braves at Chicago Cubs and Toronto Blue Jays at Cleveland Indians games also were rained out Sunday.

The prolonged wintry weather is "starting to beat everybody down," said Erik Ordal, who lives in downtown Minneapolis and was taking his 3-month-old golden retriever puppy, Dakota, out for a walk in the snow. Ordal, who grew up in South Dakota, said he is used to the cold, snowy weather "but I'm certainly ready for some warmth."

Two northeastern Wisconsin communities, Tigerton and Big Falls, received more than 2 feet of snow over the weekend, the National Weather Service in Green Bay reported. Parts of the state that were already blanketed were getting a second helping of snow on Sunday. The heavy snow caused part of a hotel roof to collapse over a pool at a hotel in Ashwaubenon, which is next to Green Bay, but no one was in the pool area at the time and no one was hurt.

The storm finally let up in South Dakota, allowing the airport in the state's largest city, Sioux Falls, to reopen for the first time since Thursday. Interstates 90 and 29 in parts of eastern South Dakota also reopened, and no-travel advisories were lifted across the state border in southwestern Minnesota.

In Michigan, freezing rain that began falling overnight had left roads treacherous and cut power to hundreds of thousands of homes and businesses by midday Sunday even as heavy snow was forecast to dump a foot or more of snow on parts of the state's Upper Peninsula by early Monday.

To the south, officials in Lexington County, South Carolina, said several buildings were damaged and toppled trees were blocking roads, but no injuries were reported.

Tens of thousands of homes and businesses in the Carolinas were without power Sunday.

In Arkansas, a tornado ripped through the tiny Ozark Mountain town of Mountainburg on Friday, injuring at least four people. In Texas, hail the size of hen eggs fell south of Dallas, according to meteorologist Patricia Sanchez.

And another round of snow is possible midweek in the Upper Midwest, said meteorologist Eric Ahasic at the National Weather Service in Chanhassen, Minnesota.

"It's not going to be as much snow as this one, thankfully," Ahasic said.