Amarillo firefighters aid victims still in their vehicles after a major pileup Saturday on I-40 near Pullman Road in Amarillo, Texas. About 80 vehicles were involved in the massive pileup that resulted in at least one fatality and shutdown Interstate 40 and Highway 287 for much of the day.

Amarillo, Texas ? A blinding snowstorm blew across the Plains on Saturday, causing at least two deaths and dozens of injuries in numerous multi-car pileups and forcing authorities to close portions of several major highways.

One person died in a chain-reaction pileup involving more than 50 vehicles, including several tractor-trailer rigs, on Interstate 40, police said. Authorities said it would take a few days to determine exactly how many were involved.

Eighteen people were taken to hospitals, two with life-threatening injuries, Sgt. Michael Poston said.

“There were cars crashing while they (firefighters) were there,” Fire Department Capt. Bob Johnson told the Amarillo Globe-News for its Sunday editions. “They could hear them (the crashes), but they couldn’t see them.”

Many in the pileup were holiday travelers, including families with small children not dressed for the weather, Sgt. Shawn McLeland. Other drivers spotted them and opened Christmas presents to provide warmer clothing for the children.

The tangle of twisted cars and trucks shut down the interstate for most of the day. Authorities believe the pileup was caused by blowing snow and the resulting zero visibility.

The fierce snowstorm caused another wreck involving 20 to 40 vehicles, including three tractor-trailer rigs, on Interstate 29 in St. Joseph in western Missouri. Police closed about 100 miles of I-29 to the Iowa state line.

The Plains storm also blew heavy snow across Oklahoma and parts of Nebraska and Iowa, a region still recovering from a severe ice storm early last week that knocked out electricity for hundreds of thousands of homes and businesses.

“We may see some whiteouts in the open areas,” said Craig Cogil, a forecaster with the National Weather Service in Des Moines, Iowa. Parts of the state could get between 6 and 10 inches of snow by Sunday morning.

Strong winds could make traveling hazardous all weekend, Cogil said.

Wind was blowing at sustained speeds of 25 to 35 mph with gusts to 45 mph in Oklahoma, where U.S. 412 near Mooreland in western Oklahoma was closed after 15 to 20 cars slid off the road or had been involved in collisions, authorities said.

The Oklahoma Highway Patrol said a six-car collision on U.S. 64 in the state’s northwest corner involved an ambulance that was carrying victims from the scene of another accident. Low visibility forced the closure of some highways.

Farther west, Colorado roads remained icy in spots following a storm Friday. Eastbound I-70 was closed about 20 miles east of Denver for more than two hours after a wreck in which five people, including an 8-year-old girl, were injured.

The storm also impacted flights at airports in the Midwest, as the busy pre-Christmas weekend travel was getting underway. The delays rippled across the country, affecting flights in the New York region.

In Chicago, flights in and out of O’Hare International Airport were delayed an average of two hours, and about 100 flights were canceled, airport spokesman Gregg Cunningham said.

Flights departing from Newark Liberty International Airport for O’Hare were delayed about three hours.