CHICAGO (AP) — A powerful, gusty storm dumped mounds of snow across the upper Midwest on Sunday, closing major highways in several states, canceling more than 1,600 flights in Chicago.

At least four weather-related deaths were reported as the storm system dropped nearly 2 feet of snow in parts of Minnesota and marched east. A blizzard warning was in effect Sunday for parts of eastern Iowa, southeastern Wisconsin, northwestern Illinois and northern Michigan, according to the National Weather Service. Surrounding areas, including Chicago, were under winter storm warnings. Much of Iowa was under a wind-chill advisory.

The wintry weather, with blowing snow that severely limited visibility, wreaked havoc on air and road travel. In the Chicago area, wind gusts of up to 50 mph, temperatures in the teens and wind chills well below zero were expected, along with up to 8 inches of snow.

At least 1,375 flights were canceled at O’Hare International Airport and more than 300 were canceled at Midway International Airport, Chicago Department of Aviation spokeswoman Karen Pride said. Both airports expected more cancellations and reported significant delays.

Officials at O’Hare set up about 200 cots and will provide amenity kits containing toothpaste and toothbrushes in case travelers get stranded at the airport, Pride said.

Major highways in several states were closed due to poor driving conditions and accidents.

In Indianapolis, police said a man fatally stabbed his wife, then died four blocks from his home Sunday morning when his vehicle hit a tree after he lost control on a slippery road. Police did not immediately release the names of the couple.

Illinois State Police closed a section of Interstate 80 in the north central part of the state after a multiple-car pileup west of Peru and part of Interstate 55 near Springfield after accidents and reports of zero visibility. No deaths were reported.

Seven vehicles crashed on Interstate 94 about 50 miles west of Milwaukee, prompting authorities to close the westbound lanes. A vehicle lost control on an ice-covered road and slammed into a tree in southeastern Wisconsin, killing 21-year-old Alejandria Abaunza of Chicago and injuring two other people inside.

Tod Pritchard of Wisconsin Emergency Management warned that Sunday afternoon would be especially difficult because temperatures were falling and at a certain point, road salt would no longer be effective.

The storm had already dropped up to 18 inches of snow in parts of northern and central Wisconsin.