Yet another storm swept across the central United States, burying areas still recovering from an earlier wave of severe weather, tying up air travel and killing at least four people.

A 40-car pileup on Interstate 40 in northern Texas that killed at least one person was caused by blowing snow that limited visibility and left icy patches Thursday, said Wayne Beighle, a Texas Department of Public Safety trooper.

The storm has been blamed for at least three other deaths: two in Texas and one in Oklahoma.

Elswhere in Texas, firefighters in several counties battled wind-driven wildfires, including a 2,000-acre (800-hectare) blaze northwest of Fort Worth that was expected to be contained later Thursday.

The storm pounded areas of the Midwest still rebounding from storms earlier in the week that spawned a mix of snow, brutal cold, tornadoes and hail.

More than 600 flights in and out of Chicago's O'Hare International Airport, one of the nation's busiest, were canceled, and others were delayed an average of two hours. Flights were also canceled at some other area airports, including Indianapolis, where 6 inches to 8 inches (15 to 20 centimeters) of snow was to predicted to fall.

In the West, searchers found the body of a Colorado man who died on snowmobiling trip in the mountains west of Denver.

John McKibben and two companions got lost during a one-day outing Sunday. The other two men were rescued Tuesday but told search crews that McKibben died Monday night.